Mobile-Terminated (MT) Early Data Transmission (EDT) in Control Plane and User Plane Solutions

This disclosure describes methods, systems, and devices for mobile terminated, MT, early data transmission, EDT. A method involves receiving (602), for a user equipment, UE, UE MT EDT capability information, receiving (604) an indication of downlink data for transmission to the UE. Furthermore, based on the UE MT EDT capability information, to initiate (606) MT EDT to transmit the downlink data to the UE and then initiating MT EDT to send (608) the downlink data to the UE.

TECHNICAL FIELD

This disclosure relates generally to signaling in wireless communication systems.

BACKGROUND

User equipment (UE) can wirelessly communicate data using wireless communication networks. To wirelessly communicate data, the UE connects to a node of a radio access network (RAN) and synchronizes with the network.

SUMMARY

This disclosure describes methods, systems, and devices for mobile terminated (MT) early data transmission (EDT).

In accordance with one aspect of the present disclosure, a method involves receiving, for a user equipment (UE), UE MT EDT capability information. The method further involves receiving an indication of downlink data for transmission to the UE. The method also involves determining, based on the UE MT EDT capability information, to initiate MT EDT to transmit the downlink data to the UE. Further, the method involves in response to the determination, initiating MT EDT to send the downlink data to the UE-RNTI). Further, the method involves transmitting the RRC paging message to the UE.

Other versions include corresponding systems, apparatus, and computer programs to perform the actions of methods defined by instructions encoded on computer readable storage devices. These and other versions may optionally include one or more of the following features.

In some implementations, the UE MT EDT capability information indicates that the UE supports a maximum MT EDT transport block size (TBS).

In some implementations, the UE capability information is provided by the UE as part of an RRC connection establishment procedure.

In some implementations, determining to initiate MT EDT is further based on at least one of size information of the downlink data, a release assistance indication (RAT), or an MT EDT operation preference of the UE.

In some implementations, receiving an indication of downlink data for transmission to the UE includes receiving, via control plane signaling by the MME and from the S-GW, the indication of the downlink data, where the control plane signaling is extended to include downlink data size information.

In some implementations, receiving an indication of downlink data for transmission to the UE includes receiving, via control plane signaling by the MME and from the S-GW, the downlink data, where the control plane signaling is extended to include the downlink data.

In some implementations, the method further includes transmitting the downlink data to the UE in a downlink Radio Resource Control (RRC) message.

In some implementations, the method further includes receiving an acknowledgment of receipt from a recipient UE, and determining, based on the acknowledgment, that the recipient UE is the UE intended to receive the downlink data.

In some implementations, the acknowledgment of receipt is a non-access stratum (NAS) security token received via layer 2 (L2) signaling with the recipient UE.

In some implementations, the acknowledgment of receipt is received via a network resource that is assigned as a non-access stratum (NAS) security token ID to the UE.

In accordance with another aspect of the present disclosure, a method involves receiving, by a next-generation NodeB (gNB) of the NG-RAN, an MT EDT indication and information indicative of downlink data for transmission to a user equipment (UE) served by the gNB, wherein the UE is in an Connection Management-Idle (CM-Idle) mode; based on the information indicative of the downlink data, determining to initiate MT EDT to transmit the downlink data to the UE; generating a Radio Resource Control (RRC) paging message comprising: (i) the MT EDT indication and (ii) an indication of a contention free (CF) physical random access channel (PRACH) resource; and transmitting the RRC paging message to the UE.

Other versions include corresponding systems, apparatus, and computer programs to perform the actions of methods defined by instructions encoded on computer readable storage devices. These and other versions may optionally include one or more of the following features.

In some implementations, the method may further involve receiving, from the UE, an RRC response message to the RRC paging message; sending to Access and Mobility Management Function (AMF) a request for the downlink data; and receiving, from the AMF, a downlink non-access stratum (NAS) protocol data unit (PDU).

DETAILED DESCRIPTION

Narrow band-Internet of Things (NB-IoT) is a technology that is designed to address specific cellular IoT (CIoT) constraints. NB-IoT can provide improved indoor coverage, support for a relatively large number of low throughput devices, low delay sensitivity, low device cost, low device power consumption, and an improved network architecture. NB-IoT can be deployed in either the Global System for Mobile Communications (GSM) spectrum or the Long Term Evolution (LTE) spectrum. NB-IoT can also be deployed in Fifth Generation (5G) or New Radio (NR) technologies.

NB-IoT also supports control plane (CP) and user plane (UP) optimization solutions. The CP solution, referred to as a CP CIoT evolved packet system (EPS) optimization, can enable support of an efficient transport of user data (e.g., Internet Protocol (IP) data or non-IP data) or short messaging service (SMS) messages over the control plane via a mobility management entity (MME) without necessitating an establishment of a data radio bearer. CP CIoT EPS optimization may do so by transmitting CP data transmitted over a non-access stratum (NAS). The UP solution, referred to as a UP CIoT EPS optimization, enables a user equipment (UE) to resume a previously stored Radio Resource Control (RRC) connection. The UP solution does so by storing a UE access stratum (AS) context in the access node (e.g., eNodeB (eNB)) and storing the UE AS context on the UE. The UP solution enables changing from an EPS Mobility Management (EMM) idle mode to an EMM connected mode without using a service request procedure.

Furthermore, NB-IoT can provide support for early data transmission (EDT), which facilitates infrequent small data packet transmissions. In particular, EDT can facilitate data transmission from and/or to a UE that is in an idle or suspended state without having the UE transition to a connected state. As such, EDT achieves data transmission without resuming an RRC connection. In some implementations, a small data transmission can be appropriate for EDT transmissions if the data does not exceed a predetermined threshold, e.g., transmissions that are less than N bytes, where N is a predetermined value, e.g., 100, 128, 256, 512, and 1024. Other values for N are possible.

In practice, a mobile originated (MO) EDT solution exists. This solution enables uplink (UL) data to be transmitted in Msg3 and downlink (DL) data to be transmitted in Msg4. However, existing systems do not support transmission of DL data in Msg4 without first transmitting UL data in Msg3. That is, existing systems do not support mobile terminated (MT) EDT. However, such a solution may have many advantages, including improved DL transmission efficiency and/or UE power consumption. As such, there is a need to develop a MT EDT solution.

This disclosure describes systems and methods for implementing an MT EDT solution for UEs that may be using CP and/or UP C-IoT EPS optimization. In particular, this disclosure describes Msg2-based techniques and Msg4-based techniques that may be used for DL data transmission. Furthermore, this disclosure describes implementation details for the Msg2-based techniques and Msg4-based techniques. Note that although this disclosure generally describes the systems and methods in the context of CP DL data transmission, the systems and methods can also be applied to UP DL data transmission.

FIG. 1illustrates an example messaging diagram100of a Msg2-based technique for transmitting downlink (DL) control plane data (CP) to a user equipment (UE), according to some implementations. In an embodiment, a wireless communication system may implement MT EDT using the Msg2-based technique (also referred to as a “Msg2-based solution”). As shown inFIG. 1, the wireless communications system includes an MME130, an S-GW140, and eNB150. The eNB150is an access point (AP) of a radio access network (RAN) that serves a UE160. In this example, the UE160may be configured to use CP CIoT EPS Optimization. Furthermore, in this example, the S-GW140provides the DL CP data, but in other examples, an SCEF may provide the DL CP data (e.g., to the MME130). Note that although a single eNB and a single UE are shown inFIG. 1, the wireless communication system may include a plurality of eNBs and/or a plurality of UEs.

The Msg2-based technique starts at step102of the messaging diagram100. At step102, the S-GW140(or the SCEF) sends CP data information to the MME130. The CP data information may include an indication of DL CP data arrival and/or size information of the DL data. In an example, the DL CP data may arrive in the S-GW140, which may generate and send the CP data information to the MME130. At step104, and after receipt of the CP data information, the MME130initiates MT EDT. In some examples, when the CP DL data arrives at the S-GW140, the data can be made available to the MME130, perhaps by forwarding the data to the MME130.

The MME130determines to initiate MT EDT to send the CP DL data to the UE160. The MME130then generates an S1-AP paging message that includes an MT EDT indication and the CP data information. Then, at step106, the MME130transmits the S1-AP paging message to the eNB150. At step108, and after receipt of the S1-AP paging message, the eNB150determines whether to use MT EDT to transmit the DL data to the UE160. The eNB150can make the determination based on UE capability (e.g., whether the UE is capable of MT EDT). If the eNB150decides to use MT EDT, the eNB150then determines a contention free (CF) Physical Random Access Channel (PRACH) resource index, a preamble index, and/or an EDT-Radio Network Temporary Identifier (EDT-RNTI). This information may be collectively referred to as MT EDT information. This information enables the UE160to transmit Msg1 and to determine the EDT-RNTI to use to receive Msg2. Further, the EDT-RNTI information may be a specific EDT-RNTI (e.g., a reserved EDT-RNTI) or an offset value to the EDT-RNTI.

At step110, the eNB150sends a paging message (e.g., an RRC message) to the UE160. Among other things, the paging message includes an MT EDT indication, the CF PRACH resource, and/or the EDT-RNTI. At step112, and after receipt of the paging message by the UE160, the UE160responds to the paging message using the received CF PRACH resource. As shown inFIG. 1, the UE160responds using Msg1, which may include the CF preamble (used to receive the RRC message). At step114, and after receipt of Msg1, the eNB150identifies the UE160, perhaps based on the CF preamble included in Msg1. The eNB150also generates an S1-AP initial message to send to the MME130. The initial message may include a request to send the DL CP data.

At step116, the eNB150sends the S1-AP initial message to the MME130. At step118, and in response to receipt of the S1-AP initial message, the MME130sends the DL CP data (e.g., a NAS PDU) to the eNB150. At step120, the eNB150sends an RRC message (Msg2) to the UE160. The Msg2 may include the DL CP data, perhaps in dedicatedinfoNAS. In this technique, because the CP DL data is sent in the NAS PDU, the data can be protected by NAS security. The UE160may be monitoring a Physical Downlink Control Channel (PDCCH) using the EDT-RNTI information in order to receive the DL CP data. In an example, the UE160determines the specific EDT-RNTI resource to monitor based on the EDT-RNTI information included in the paging message. The UE160may then receive Msg2 via the monitored resource. In some examples, the eNB150may also send the UE160a Random Access Response (RAR) containing a timing advance (TA) and an UL grant, which the UE160may use for an UL ACK transmission. The UE160may receive the RAR in the same Msg2 or in a separate message.

At step122, the UE160transmits, using the UL grant provided in the RAR, an RRC message (Msg3) that includes a NAS PDU. The NAS PDU may be a NAS ACK or an UL ACK to the received CP DL data. At step124, the eNB150forwards the NAS PDU to the MME130. Furthermore, as indicated by block126, if the ACK contains NAS signaling, the network can determine whether the UE is fake (e.g., an unintended recipient). If the UE is fake, the procedure100is repeated.

FIG. 2illustrates an example messaging diagram200of a Msg4-based technique for transmitting downlink (DL) control plane data (CP) to a device, according to some implementations. In this example, the wireless communication system described with respect toFIG. 1implements MT EDT using the Msg4-based technique (also referred to as a “Msg4-based solution”). The Msg4-based technique starts at step202of the messaging diagram200. At step202, the S-GW140(or the SCEF) sends CP data information to the MME130. In some examples, when the CP DL data arrives at the S-GW140, the data can be made available to the MME130, perhaps by forwarding the data to the MME130. At step204, and after receipt of the DL data, the MME130determines to initiate MT EDT to send the CP DL data to the UE160. The MME130also generates an S1-AP paging message that includes an MT EDT indication and DL data information.

At step206, the MME130transmits the S1-AP paging message to the eNB150. At step208, and after receipt of the S1-AP paging message, the eNB150determines whether to use MT EDT to transmit the CP DL data to the UE160. The eNB150can make the determination based on UE capability. If the eNB150decides to use MT EDT, the eNB150generates a paging message than includes an MT EDT indication. At step210, the eNB150sends the paging message (e.g., an RRC message) to the UE160. At step212, and after receipt of the paging message by the UE160, the UE160responds to the paging message using Msg1 that includes an MO EDT preamble. At step214, the eNB150sends the UE160a Msg2 that includes a RAR containing an UL grant size. At step216, the UE160transmits an RRC message (Msg3) including a NAS service request. For example, the RRC message may be an RRCEarlyDataRequest message. At step218, and after receipt of Msg3, the eNB150generates an S1-AP initial message to send to the MME130. The initial message may include a request to send the DL data.

At step220, the MME130determines whether the UE is fake. If the UE is fake, then the MME130determines not to deliver DL data to the UE. Instead, the MME130sends a reject message and the procedure200is repeated. At step222, and in response to determining that the UE160is the intended recipient, the MME130sends the DL data (e.g., a NAS PDU) to the eNB150, perhaps using a DL NAS Transport message. At step224, the eNB150sends the UE160an RRC message (Msg4) that includes the DL data, perhaps in dedicatedInfoNAS. At step226, the UE160may optionally transmit to the eNB an RRC message (Msg5) that includes UL ACK data. At step228, the eNB150forwards the UE ACK and/or UL data to the MME130, which may forward the NAS PDU to the S-GW140. After successful transmission of the UL data, the MT EDT from the UE160's perspective is complete.

As explained with respect to both techniques, the S-GW provides the MME with the DL data. However, when the S-GW provides the DL may depend on the size and/or number of packets of the DL data. In an embodiment, if the DL data is a single packet and/or smaller than a predetermined threshold, then the S-GW may provide the DL data to the MME upon receipt of the DL data. For instance, in the example ofFIG. 1, the S-GW may provide the MME with the DL data in step102. However, if the DL data is more than one packet and/or larger than the predetermined threshold, then the S-GW cannot simply forward the DL data to the MME. Instead, a bearer must be established between the MME and the S-GW in order to transfer the data.

FIG. 3illustrates an example messaging diagram300of the signaling between the MME and the S-GW to transfer DL data, according to some implementations. In particular, this signaling may occur when the S-GW cannot forward the DL data to the MME (e.g., the DL data is more than one packet and/or larger than the predetermined threshold). At step302, a P-GW170provides the DL data to the S-GW140. Upon receipt of the data, the S-GW140determines whether the DL data can be forwarded to the MME130. For example, the S-GW140can make the determination based on a number of packets of the DL data and/or whether a size of the DL data exceeds a predetermined threshold. If the S-GW140determines that the DL data cannot be forwarded, then the S-GW140sends a DL data arrival indication to the MME130. Upon receipt of the indication, the MME130engages in signaling at step306with eNB(s), as described above. Later, the MME130may receive an S1-AP request of the DL data at step308. In response, at step310, the MME130engages in signaling with the S-GW140in order to establish a bearer between the MME130and the S-GW140. At step312, the S-GW140sends the DL data to the MME130via the established bearer. At step314, the MME130sends the DL data to eNB(s) using S1-AP signaling. Then, at step316, the bearer is deactivated.

MT EDT Initiation

When data arrives in the S-GW, a default S11-U tunnel may have already been established between the S-GW and the MME. In this scenario, the MME buffers the DL data (and not the S-GW). However, if a default S11-U tunnel is not established, an S11-U tunnel (e.g., an SGi packet data network (PDN) connection with Control Plane Only Indicator, See, for example, 3GPP TS 23.401, 5.10.2) may need to be established. In this scenario, the S-GW buffers the DL data and sends a DL data notification to the MME. Then, when the MME receives a service request from a UE or the MME locates a UE, the MME may request the S-GW to activate an EPS bearer in order to receive the DL data from the S-GW. Later, when the UE is released, the MME has to deactivate the EPS bearer with the S-GW. This procedure of EPS bearer establishment (e.g., establishing the S11-U tunnel) just for the purpose of small data transmission may be unnecessary and resource inefficient.

In an embodiment, the signaling between the MME and S-GW is optimized to avoid unnecessary EPS bearer establishment. In an example, the S-GW determines whether the DL data is suitable for MT EDT prior to forwarding the DL data to the MME. As such, the S-GW (or the P-GW) itself makes a preliminary decision if the DL data is suitable for MT EDT. In order to forward the DL data, the control plane signaling S11 is extended to encapsulate the DL data that is sent to the MME. In another example, the signaling between the MME and S-GW is optimized by extending the control plane signaling S11 to include DL data size information when sending a DL data arrival notification to the MME. In this example, the MME may determine whether to use MT EDT. Within examples, the DL data size information can be: (i) sent from the Application Server (AS) with the DL data, (ii) derived in the Network Exposure Function (NEF) when the DL data arrives at the NEF from the AS, (iii) derived at the MME, and/or (iv) derived at the S-GW when the DL data is received from the P-GW.

Note that in the Msg4-based technique, the EPS bearer establishment may not be an issue because a legacy signaling procedure can be used as much as possible. Thus, the EPS bearer activation and deactivation procedure can be reused. In the Msg2-based technique, however, the UE does not transmit a NAS service request, and thus, the EPS bearer establishment procedure cannot be reused. As such, in some examples, the signaling optimization may be used in the Msg2-based technique, but not the Msg4-based technique. In other examples, the signaling optimization may be used in both the Msg4-based technique and the Msg2-based technique, or just the Msg4-based technique.

When the DL data is available in the MME, the MME can determine the DL data size information and whether the DL data includes a single packet or multiple packets. For DL CP data, the MME may also receive additional information such as a release assistance indication (RAI), which may indicate whether an acknowledgement or response is expected after the data transmission (e.g., whether an uplink (UL) acknowledgement (ACK) in response to the DL data is expected). Furthermore, in some examples, the MME may determine whether to use MT EDT to transmit the DL data. In an embodiment, one or more factors may be considered by the MME when determining whether to use MT EDT. The factors include a number of packets for transmission (e.g., single or multiple DL data packets), RAI (e.g., whether further DL/UL data is expected), DL data size information, and/or MT EDT capability. In an example, the eNB may inform the MME of a maximum supported TBS size for MT EDT for a UE. The MME can store it in the local context of the UE. The UE may provide the eNB with the UE capability to support maximum MT EDT TBS size in Msg5 (e.g., RRCConnectionSetupComplete message) during an RRC connection establishment procedure.

Response to Paging Message for MT EDT

In the Msg2-based technique, a UE may use a contention free (CF) PRACH resource to respond to the paging message for MT EDT. In an example, the UE uses the CF preamble indicated by the paging message and includes the CF preamble in the response. In this example, the eNB may use the CF preamble to locate the UE. However, given that only a coverage enhancement (CE) level or a number of repetitions may be provided in the paging message, the Physical Random Access Channel (PRACH) parameters used for this CF preamble must be determined.

In an embodiment, the same non-EDT configuration may be used for Msg1 and Msg2 for the indicated CE level or number of repetitions except for those parameters explicitly or implicitly indicated by the paging message or DCI itself.

In an example, for the Msg2-based technique, a length of time that the reserved CF preamble remains valid if Msg2 has not been successfully received by the UE can be determined using one of a plurality of methods. In a first method, the length of time is based on a validity timer. In this method, the reserved CF preamble remains valid until the validity timer expires. In a second method, the length of time is based on a maximum limit to transmit CF preamble. In this method, the reserved CF preamble remains valid until a maximum limit to transmit the CF preamble is reached. In a third method, the length of time is based on an “x” number of CF preamble transmission opportunities, where “x” is a positive integer. In this method, the reserved CF preamble is valid for the next “x” number of CF preamble transmission opportunities after the reception of the paging message. In a fourth method, the reserved CF preamble is valid just for the next CF preamble transmission opportunity. Other methods are possible and are contemplated herein.

Unlike a Physical Downlink Control Channel (PDCCH) order in RRC connected mode, the CF preamble has to be reserved by a number of cells in a tracking area. Thus, it is desirable to use the preamble quickly. Because paging retransmission can be used for MT EDT, it may be unnecessary to keep the CF preamble reserved for an extended period once the UE starts monitoring the PDCCH. For example, an integer x (e.g., x≥1) can be predefined or configured such that the CF preamble is not used after the next “x” number of CF preamble transmission opportunities after the reception of the paging message. If the UE does not receive any response to the preamble transmission (e.g., assuming the network didn't receive the preamble), then the network can retransmit the paging message. Therefore, the UE can monitor P-RNTI and EDT-RNTI simultaneously. In one example, the EDT-RNTI is assigned a greater priority. In another example, the P-RNTI is prioritized over the EDT-RNTI. Alternatively, if the UE does not receive any response to the preamble transmission, the UE can decide to follow legacy procedure by transitioning to RRC connected mode.

In an embodiment, contention free preamble retransmission may be used. In an example, power ramping and/or CE level change is allowed. In another example, power ramping and/or CE level change is not allowed.

In the Msg4-based technique, upon receiving the MT EDT indication in the paging message, the UE can start using an MO EDT preamble. Since the UE may transmit a NAS service request in Msg3, the UE may need an UL grant larger than a minimum UL grant of 56 bits in RAR. Note that the UE cannot use a legacy non-EDT preamble in this scenario. One issue that may arise from using the MO EDT preamble is that the eNB may not know whether the UE is initiating MO EDT or MT EDT.

In an embodiment, one or more of following methods may resolve this issue. In a first method, a new TBS is defined for EDT. In particular, a new TBS size that is smaller than the minimum TBS (328 bits) provided in RAR may be defined. In a second method, a PRACH resource is dedicated or reserved for MT EDT. In a third method, the decision of whether to use an EDT or non-EDT preamble is left to the UE. In a fourth method, a respective CF preamble for each CE level is indicated in the paging message.

In some scenarios, a CF preamble can be included in the paging message for the Msg4-based technique. In an example, an initial CE level or repetition level is indicated in the paging message. In this example, the UE uses a legacy non-EDT or EDT RACH configuration and the PRACH resource corresponding to the indicated level (with only difference being that that CF preamble is transmitted). Furthermore, in this example, the UE receives a legacy RAR that includes an UL grant sufficient to transmit Msg3 with an NAS service request.

In another example, when the indicated CE level or repetition level for the CF preamble in the paging message has a greater quality than the UE's current CE level or repetition level, then the UE falls back to the legacy EDT or non-EDT preamble. For example, if the UE is operating in CE level 3 but paging indicates that DL data is transmitted considering CE level 0, then the UE may send a legacy non-EDT or EDT preamble for CE level 3.

In yet another example, a respective CF preamble corresponding to each CE level is indicated in the paging message. In yet another example, the initial CE level or repetition level is determined by UE based on a Reference Signal Receive Power (RSRP) threshold.

DL Data Reception

In an embodiment, in order to receive the DL data (e.g., in Msg2 or Msg4), the UE may use legacy procedures. In particular, a RAR window and a frequency hopping configuration of legacy RACH can be used. Furthermore, DCI provides the dynamic DL assignment for Msg2.

In an example, legacy RACH-ConfigCommon and PRACH-ParametersCE-r13 for non-EDT are used to receive the DL data. In another example, the RACH configuration and PRACH parameters for EDT may be used. In yet another example, new configurations for RACH and PRACH parameters may be defined for MT EDT.

After transmitting the CF preamble, the UE monitors PDCCH to receive Msg2. Although the UE may be monitoring EDT-RNTI, a legacy RAR can be sent in case the eNB decides to transition the UE to RRC connected mode. The legacy RAR may include a Temporary cell-RNTI (C-RNTI), a TA command, and an UL grant.

In an embodiment, unlike legacy Msg2, hybrid automatic repeat request (HARQ) feedback of Msg2 can be considered for fast retransmission (similar to HARQ feedback for Msg4).

In an embodiment, the UE can restart the Msg2 reception window if HARQ feedback is transmitted in the UL. Further, a maximum Msg2 HARQ retransmission limit can be defined, perhaps similar to a legacy Msg3 HARQ retransmission limit. In one example, the UE transmits HARQ NACK only if the UE does not successfully receive Msg2.

Response to DL Data

In some scenarios, the UE may move to a different cell. However, if the UE moves, the UE may be in a worse coverage level than the last time it was in RRC Connected mode. But the eNB may transmit the paging message assuming that the UE has a better coverage level. As such, the intended UE may miss the paging message while a fake UE (e.g., an attacker) may respond to the paging message. Or the network may not receive the preamble from the intended UE while it does so from the fake UE.

In the Msg2-based technique, the MME sends the DL data before receiving any NAS signaling from the legitimate UE. Since the eNB may not be able to guarantee that it received the preamble from the intended UE and that DL data is sent to the intended UE (as any fake UE may send the preamble), a secured signaling is needed from the UE as an acknowledgment of the Msg2 with the DL data.

In an embodiment, a mechanism to acknowledge that Msg2 was received by the intended UE may be used. For this purpose, the eNB can additionally provide a TA command and an UL grant. The UE can send an UL NAS PDU with a NAS acknowledgement. In this case, the UE needs to transmit the UL ACK of the received DL, data, and thus, the UL. NAS PDU can contain the application UL ACK data. In an example, a dedicated UE specific PUCCH configuration can also be used for the acknowledgment provided that such configuration is not shared with other UEs.

For the Msg2-based technique, the following mechanisms can be used to acknowledge that Msg2 was received by the intended UE. In a first mechanism, a dedicated UE specific Layer 1 (L1) signaling as ACK/NACK is used. In a second mechanism, Layer 2 (L2) signaling to carry a NAS security token (e.g., 16 bit UL NAS MAC and 5 bit UL NAS count) may be used. In a third mechanism, an L1 or L2 ACK in PUSCH using a RNTI that is assigned by MME as a 16 bit NAS security token ID to UE may be used. In a fourth mechanism, an RRC message carrying NAS signaling or UL data for DL data feedback may be used.

For the Msg4-based technique, the MME can identify the legitimate UE from a NAS service request before the CP DL data is sent. Therefore, a secured mechanism to acknowledge that Msg2 was received by the intended UE is not needed.

However, in some scenarios, the Msg4-based technique may send the UE back to IDLE mode without an opportunity for the UE to transmit application UL data (e.g., as feedback to the DL data). On the other hand, in the Msg2-based technique, the eNB may provide an UL grant in Msg2 regardless of whether the UE needs to transmit UL application feedback data, perhaps because a NAS security token may be needed in the uplink. However, in some scenarios, a size of the UL application feedback data may be larger than the NAS signaling PDU.

In an example, the network (e.g., by way of the eNB) may, by default, provide a sufficient UL grant together with the MT EDT data so that the UE may transmit application UL data. In another example, the network may schedule the UL grant after transmission of the MT EDT data based on the UE's message processing time (e.g., Msg2 or Msg4). Once the UL grant is received or an indication of scheduling (e.g., an UL grant) is provided in Msg2 or Msg4, the UE may delay a release procedure or going back to IDLE mode in order to receive the UL grant and complete the Physical Uplink Control Channel (PUSCH) transmission.

In an embodiment, when the UE sends an RRC connection request to transition to RRC connected mode, the UE may indicate its preference to receive an UL grant to transmit application UL data in Msg5 (e.g., in an RRCConnectionSetupComplete message). The MME stores this information in the UE's context and provides it to the eNB when MT EDT is initiated.

UE Capability Indication to Support MT-EDT

In an embodiment, the UE may indicate its capability to support MT-EDT. In an example, a UE may indicate its support for MT-EDT as UE Core network capability information sent to the MME in an attach request during an attach procedure. If the UE supports MT-EDT as indicated in the UE Network Capability, the MME may consider this parameter as one of the inputs to initiate MT-EDT for DL data.

MT-Release Assistance Indication from the Service Capability Server/Application Server (SCS/AS) Via Service Capability Exposure Function (SCEF)

In an embodiment, to support MT-EDT transmission in a Non IP Data Delivery (NIDD) Procedure, the SCS/AS may send an MT-Release Assistance Indicator with the non-IP Data in the MT NIDD Submit Request sent to the SCEF. The indicator may be indicative of a Single Downlink packet transmission and/or Dual Downlink packet transmission (DL with subsequent UL).

SGi Tunnel Parameter to Support MT-EDT Via P-GW Connectivity

In an embodiment, to support MT-EDT transmission in the Mobile Terminating Data Transport with P-GW Connectivity, a SGi PtP tunneling based on UDP/IP is used to deliver non-IP data. In an example, the tunnel parameters (e.g., destination IP address, UDP port, MT-EDT) for the SGi tunneling are pre-configured on the P-GW. The MT-EDT tunnel parameter indicates that the associated User Datagram Protocol (UDP) port shall be used for MT-EDT.

MT NIDD Procedure to Support MT-EDT (with Respect to EPS)

In an embodiment, the network may support an MT NIDD Procedure for MT-EDT (with respect to EPS). In a first step of the procedure, the SCEF includes the MT-Release Assistance Indicator in the NIDD Submit Request sent to the MME. In a second step, if the UE is in ECM_IDLE, based on the MT-EDT capability of the UE and MT-Release Assistance Indicator received from the SCEF, the MME determines to include the MT-EDT indicator, DL Data Size, and/or an MT-Release Assistance Indicator (if sent from the SCEF to the MME) in the paging message to the eNBs. In a third step, the IE is paged by the eNBs. In a fourth step, the UE responds with an RRC message that uses the preamble indicated by the paging message from the eNB. In a fifth step, the eNB sends an initial UE message with the downlink data request indicator to the MME. In a sixth step, the MME responds with a DL NAS transport message with the DL data PDU. In a seventh step, the eNB delivers the DL data to the UE. In an eighth step, the UE acknowledges the data delivery with a NAS ACK and/or UL Data (if any). In a ninth step, the eNB forwards the NAS ACK to the MME. In a tenth step, the MME sends a NIDD Submit Response to the SCEF acknowledging the NIDD Submit Request from the SCEF.

MT Data Transport Control Plane Optimization Procedure to Support MT-EDT (with Respect to EPS)

Also disclosed is an MT Data Transport Control Plane Optimization Procedure to support MT-EDT (with respect to EPS).

FIG. 4illustrates an example messaging diagram400of an MT Data Transport Control Plane Optimization Procedure, according to some implementations. As shown inFIG. 4, the procedure may be implemented by a wireless communication system that includes an MME432, an S-GW440, a P-GW470, and an eNB450. The eNB450is an access point (AP) of a radio access network (RAN) that serves a UE460. As shown by block of402, the UE460is in ECM idle mode. In an embodiment, the AS sends DL data over the SGi tunnel pre-configured for MT-EDT. When the P-GW470receives the data on the UDP port pre-configured for MT-EDT, it forwards the DL data, at step404, to the S-GW440via the corresponding EPS bearer. Upon receiving the DL data, the S-GW440, at step406, forwards the data to the MME432if an S11-U tunnel is established. Otherwise, the S-GW440sends a DL data notification message to the MME432with the DL data size information. After this step, the procedure continues using the same steps, starting with the second step, of the MT NIDD Procedure to support MT-EDT (with respect to EPS).

In an embodiment, if the information indicative of UE MT-EDT capability is available in the MME432, the MME432includes an MT-EDT indicator, DL data size information, and/or an MT-Release Assistance Indicator in the S1-AP Paging message(s). At step408, the MME432may send the S-GW440an Ack message. If the eNB450receives paging messages from the MME432, at step410, the UE is paged by the eNB450, at step412. At step414, an RRC UL message is sent from the UE460to the eNB450with the preamble sent in the paging message in step412. At step416, the eNB450sends an S1-AP initial message with DL data request to the MME432. At step418, if the S11-U is not already established, steps418,420, and422are executed. At step422, the buffered DL Data (if S11-U was not established) is sent from the S-GW440to the MME432. At step424, the MME432encrypts and integrity protects the DL data and sends it to the eNB450using a NAS PDU carried by a DL S1-AP message. At step426, the NAS PDU with data is delivered to the UE460via a DL RRC message. At step428, the NAS acknowledgement with option UL data is delivered to the eNB450via an UL RRC message. At step430, the eNB450sends an Uplink S1-AP message with NAS to the MME432.

UE Capability Indication to Support MT-EDT (with Respect to 5GS)

In an embodiment, a UE may indicate its support for MT-EDT as UE Mobility Management (MM) Core network capability information sent to the Access and Mobility Management Function (AMF) in a registration request during a registration procedure. If the UE supports MT-EDT as indicated in the UE MM Core Network Capability, the AMF shall consider this parameter as one of the inputs to initiate MT-EDT for DL Data.

MT-Release Assistance Indication from the AS/SCS Via NEF

In an embodiment, to support MT-EDT transmission in the NIDD Procedure, the SCS/AS sends an MT-Release Assistance Indicator with the non-IP Data in the MT NIDD Submit Request sent to the Network Exposure function (NEF) to indicate: (i) Single Downlink packet transmission or (ii) Dual Downlink packet transmission (e.g., DL with subsequent UL).

SGi Tunnel Parameter to Support MT-EDT Via UPF

In an embodiment, to support MT-EDT transmission in the Mobile Terminating Data Transport with User Plane Function (UPF), N6 PtP tunneling based on UDP/IP may be used to deliver non-IP data. The tunnel parameters (e.g., destination IP address, UDP port, MT-EDT) for the N6 tunneling may be pre-configured on the SMF/UPF. The MT-EDT tunnel parameter indicates that the associated UDP port shall be used for MT-EDT.

MT NIDD Procedure to Support MT-EDT (with Respect to 5GS)

Also disclosed is an MT NIDD Procedure for MT-EDT (with respect to 5GS).

In a first step of the procedure, an Application Function (AF) sends the MT-Release Assistance Indicator Nnef_NIDD_Delivery Request to the Network Exposure Function (NEF). In a second step, the NEF includes the MT-Release Assistance Indicator in the Nnef_NIDD_Delivery Request sent to the Session Management Function (SMF). In a third step, the SMF forwards the Data with the MT-Release Assistance Indicator to the Access and Mobility Management Function (AMF) in the Namf_Communication_NIN2MessageTransfer message. In a fourth step, if the SMF receives an MT-Release Assistance Indicator, when the UE is in Connection Management (CM)-IDLE and the AMF is aware of the UE MT-EDT capability, the AMF initiates paging procedure and includes MT-EDT Indicator, Downlink Data Size, and MT-Release Assistance Indicator (optionally if sent from the NEF) in the paging message to the NG-RAN.

In a fifth step, the UE is paged by the NG-RAN (e.g., gNB). In a sixth step, the UE responds with the RRC message that uses the preamble indicated by the Paging message from the NG-RAN. In a seventh step, the NG-RAN sends the UL NAS message with the Downlink Data request indicator to the AMF. In an eight step, the AMF responds with a Downlink NAS transport message with the Data PDU. In a ninth step, the NG-RAN delivers the Downlink Data to the UE. In a tenth step, the UE acknowledges the data delivery with a NAS ACK and optionally with the UL Data, if any. In an eleventh step, the NG-RAN forwards the NAS ACK to the AMF. In a twelfth step, the AMF sends the NAS ACK to the SMF, perhaps in Namf_Communication_N1N2MessageTransfer message. In a thirteenth step, the SMF sends an Nsmf_NIDD Delivery Response to the NEF. In a fourteenth step, the NEF sends a Nnef_NIDD_Delivery Response to the AF acknowledging the data delivery to the UE.

MT Data Transport Control Plane Optimization Procedure to Support MT-EDT (with Respect to 5G Systems (5GS))

Also disclosed is an MT Data Transport Control Plane Optimization Procedure to support MT-EDT (with respect to 5GS).

FIG. 5illustrates an example messaging diagram500of an MT Data Transport Control Plane Optimization Procedure with respect to a 5G System (5GS), according to some implementations. As shown inFIG. 5, the 5GS may include a UPF570, an SMF540, an AMF530, and a NG-RAN550(or node thereof, such as a gNB). As also shown inFIG. 5, the NG-RAN550serves a UE560.

In an embodiment if the UE560is in CM-Idle, the AMF530, at step502, sends a paging message to the NG-RAN550. The AMF530may include in the paging message an MT-EDT indication and/or size information of the DL data. The AMF530may also include information on UE MT-EDT capability if the information is available in the AMF530. At step504, if the NG-RAN550received a paging message from AMF530, the NG-RAN550performs paging. In particular, the NG-RAN550may generate a paging message that is sent to the UE560. The paging message (e.g., a DL RRC) may include a preamble (e.g., a preamble index). At step506, an UL RRC message is sent from UE560to the NG-RAN550with the preamble sent in the paging message from step504. At step508, the NG-RAN550sends an UL NAS transport message with DL Data request to the AMF530. At step510, the AMF530sends the DL Data request to the SMF540in a Namf_Communication_N1N2MessageTransfer message.

At step512, the SMF540indicates to the UPF570to deliver buffered data to the SMF540in an N4 Session Modification Request. At step514, the UPF570sends an N4 Session Modification Response, and at516, the buffered data is delivered to the SMF540. At step518, the SMF540compresses the header if header compression applies to the PDU session and encapsulates the downlink data as payload in a NAS message. Further, the SMF540forwards the NAS message and the PDU session ID to the AMF530using the Namf_Communication_NIN2MessageTransfer service operation. At step520, the AMF530sends the DL NAS transport message to NG-RAN550. At step522, the NG-RAN550delivers the NAS payload over RRC to the UE560. At step524, the UE560sends the NAS acknowledgement message over RRC to the NG-RAN550. At step526, the NG-RAN550sends the NAS acknowledgement message to the AMF530in the DL NAS transport message.

FIGS. 6A and 6Billustrate flowcharts of example processes, according to some implementations. For clarity of presentation, the description that follows generally describes the processes in the context of the other figures in this description. For example, process600can be performed by a base station (e.g., eNB150ofFIG. 1). As another example, the process610may be performed by a gNB. However, it will be understood that the processes may be performed, for example, by any suitable system, environment, software, and hardware, or a combination of systems, environments, software, and hardware, as appropriate. In some implementations, various steps of the processes can be run in parallel, in combination, in loops, or in any order.

FIG. 6Ais a flowchart of an example method600for mobile terminated (MT) early data transmission (EDT). At step602, the method involves receiving, for a user equipment (UE), UE MT EDT capability information. At step604, the method involves receiving an indication of downlink data for transmission to the UE. At step606, the method involves determining, based on the UE MT EDT capability information, to initiate MT EDT to transmit the downlink data to the UE. At step608, the method involves in response to the determination, initiating MT EDT to send the downlink data to the UE.

In some implementations, the UE MT EDT capability information indicates that the UE supports a maximum MT EDT transport block size (TBS).

In some implementations, the UE capability information is provided by the UE as part of an RRC connection establishment procedure.

In some implementations, determining to initiate MT EDT is further based on at least one of size information of the downlink data, a release assistance indication (RAI), or an MT EDT operation preference of the UE.

In some implementations, receiving an indication of downlink data for transmission to the UE includes receiving, via control plane signaling by the MME and from the S-GW, the indication of the downlink data, where the control plane signaling is extended to include downlink data size information.

In some implementations, receiving an indication of downlink data for transmission to the UE includes receiving, via control plane signaling by the MME and from the S-GW, the downlink data, where the control plane signaling is extended to include the downlink data.

In some implementations, the method further includes transmitting the downlink data to the UE in a downlink Radio Resource Control (RRC) message.

In some implementations, the method further includes receiving an acknowledgment of receipt from a recipient UE; and determining, based on the acknowledgment, that the recipient UE is the UE intended to receive the downlink data.

In some implementations, the acknowledgment of receipt is a non-access stratum (NAS) security token received via layer 2 (L2) signaling with the recipient UE.

In some implementations, the acknowledgment of receipt is received via a network resource that is assigned as a non-access stratum (NAS) security token ID to the UE.

FIG. 6Bis a flowchart of an example method610for mobile terminated (MT) early data transmission (EDT). At step612, the method involves receiving, by a next-generation NodeB (gNB) of the NG-RAN, an MT EDT indication and information indicative of downlink data for transmission to a user equipment (UE) served by the gNB, wherein the UE is in an Connection Management-Idle (CM-Idle) mode. At step614, the method involves based on the information indicative of the downlink data, determining to initiate MT EDT to transmit the downlink data to the UE. At step616, the method involves generating a Radio Resource Control (RRC) paging message comprising: (i) the MT EDT indication and (ii) an indication of a contention free (CF) physical random access channel (PRACH) resource. At step618, the method involves transmitting the RRC paging message to the UE.

In some implementations, the method may further involve receiving, from the UE, an RRC response message to the RRC paging message; sending to Access and Mobility Management Function (AMF) a request for the downlink data; and receiving, from the AMF, a downlink non-access stratum (NAS) protocol data unit (PDU).

The example process shown inFIGS. 6A and 6Bcan be modified or reconfigured to include additional, fewer, or different steps (not shown inFIGS. 6A and 6B), which can be performed in the order shown or in a different order.

FIG. 7illustrates an example architecture of a system700of a network, in accordance with various embodiments. The following description is provided for an example system700that operates in conjunction with the LTE system standards and 5G or NR system standards as provided by 3GPP technical specifications. However, the example embodiments are not limited in this regard and the described embodiments may apply to other networks that benefit from the principles described herein, such as future 3GPP systems (e.g., Sixth Generation (6G)) systems, IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.), or the like.

As shown byFIG. 7, the system700includes UE701aand UE701b(collectively referred to as “UEs701” or “UE701”). In this example, UEs701are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as consumer electronics devices, cellular phones, smartphones, feature phones, tablet computers, wearable computer devices, personal digital assistants (PDAs), pagers, wireless handsets, desktop computers, laptop computers, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, an Instrument Cluster (IC), head-up display (HUD) devices, onboard diagnostic (OBD) devices, dashtop mobile equipment (DME), mobile data terminals (MDTs), Electronic Engine Management System (EEMS), electronic/engine control units (ECUs), electronic/engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), networked or “smart” appliances, MTC devices, M2M, IoT devices, and/or the like.

The UEs701may be configured to connect, for example, communicatively couple, with an or RAN710. In embodiments, the RAN710may be an NG RAN or a 5G RAN, an E-UTRAN, or a legacy RAN, such as a UTRAN or GERAN. As used herein, the term “NG RAN” or the like may refer to a RAN710that operates in an NR or 5G system700, and the term “E-UTRAN” or the like may refer to a RAN710that operates in an LTE or 4G system700. The UEs701utilize connections (or channels)703and704, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below).

In this example, the connections703and704are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a GSM protocol, a CDMA network protocol, a PTT protocol, a POC protocol, a UMTS protocol, a 3GPP LTE protocol, a 5G protocol, a NR protocol, and/or any of the other communications protocols discussed herein. In embodiments, the UEs701may directly exchange communication data via a ProSe interface705. The ProSe interface705may alternatively be referred to as a SL interface705and may comprise one or more logical channels, including but not limited to a PSCCH, a PSSCH, a PSDCH, and a PSBCH.

The UE701bis shown to be configured to access an AP706(also referred to as “WLAN node706,” “WLAN706,” “WLAN Termination706,” “WT706” or the like) via connection707. The connection707can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP706would comprise a wireless fidelity (Wi-Fi®) router. In this example, the AP706is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below). In various embodiments, the UE701b, RAN710, and AP706may be configured to utilize LWA operation and/or LWIP operation. The LWA operation may involve the UE701bin RRC_CONNECTED being configured by a RAN node711a-bto utilize radio resources of LTE and WLAN. LWIP operation may involve the UE701busing WLAN radio resources (e.g., connection707) via IPsec protocol tunneling to authenticate and encrypt packets (e.g., IP packets) sent over the connection707. IPsec tunneling may include encapsulating the entirety of original IP packets and adding a new packet header, thereby protecting the original header of the IP packets.

The RAN710can include one or more AN nodes or RAN nodes711aand711b(collectively referred to as “RAN nodes711” or “RAN node711”) that enable the connections703and704. As used herein, the terms “access node,” “access point,” or the like may describe equipment that provides the radio baseband functions for data and/or voice connectivity between a network and one or more users. These access nodes can be referred to as BS, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs or TRPs, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). As used herein, the term “NG RAN node” or the like may refer to a RAN node711that operates in an NR or 5G system700(for example, a gNB), and the term “E-UTRAN node” or the like may refer to a RAN node711that operates in an LTE or 4G system700(e.g., an eNB). According to various embodiments, the RAN nodes711may be implemented as one or more of a dedicated physical device such as a macrocell base station, and/or a low power (LP) base station for providing femtocells, picocells or other like cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells.

In some embodiments, all or parts of the RAN nodes711may be implemented as one or more software entities running on server computers as part of a virtual network, which may be referred to as a CRAN and/or a virtual baseband unit pool (vBBUP). In these embodiments, the CRAN or vBBUP may implement a RAN function split, such as a PDCP split wherein RRC and PDCP layers are operated by the CRAN/vBBUP and other L2 protocol entities are operated by individual RAN nodes711, a MAC/PHY split wherein RRC, PDCP, RLC, and MAC layers are operated by the CRAN/vBBUP and the PHY layer is operated by individual RAN nodes711; or a “lower PHY” split wherein RRC, PDCP, RLC, MAC layers and upper portions of the PHY layer are operated by the CRAN/vBBUP and lower portions of the PHY layer are operated by individual RAN nodes711. This virtualized framework allows the freed-up processor cores of the RAN nodes711to perform other virtualized applications. In some implementations, an individual RAN node711may represent individual gNB-DUs that are connected to a gNB-CU via individual F1 interfaces (not shown byFIG. 7). In these implementations, the gNB-DUs may include one or more remote radio heads or RFEMs (see, e.g.,FIG. 10), and the gNB-CU may be operated by a server that is located in the RAN710(not shown) or by a server pool in a similar manner as the CRAN/vBBUP. Additionally or alternatively, one or more of the RAN nodes711may be next generation eNBs (ng-eNBs), which are RAN nodes that provide E-UTRA user plane and control plane protocol terminations toward the UEs701, and are connected to a 5GC (e.g., CN920ofFIG. 9) via an NG interface (discussed infra).

In V2X scenarios one or more of the RAN nodes711may be or act as RSUs. The term “Road Side Unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, where an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” and the like. In one example, an RSU is a computing device coupled with radio frequency circuitry located on a roadside that provides connectivity support to passing vehicle UEs701(vUEs701). The RSU may also include internal data storage circuitry to store intersection map geometry, traffic statistics, media, as well as applications/software to sense and control ongoing vehicular and pedestrian traffic. The RSU may operate on the 5.9 GHz Direct Short Range Communications (DSRC) band to provide very low latency communications required for high speed events, such as crash avoidance, traffic warnings, and the like. Additionally or alternatively, the RSU may operate on the cellular V2X band to provide the aforementioned low latency communications, as well as other cellular communications services. Additionally or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4 GHz band) and/or provide connectivity to one or more cellular networks to provide uplink and downlink communications. The computing device(s) and some or all of the radiofrequency circuitry of the RSU may be packaged in a weatherproof enclosure suitable for outdoor installation, and may include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller and/or a backhaul network.

Any of the RAN nodes711can terminate the air interface protocol and can be the first point of contact for the UEs701. In some embodiments, any of the RAN nodes711can fulfill various logical functions for the RAN710including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

According to various embodiments, the UEs701and the RAN nodes711communicate data (for example, transmit and receive) data over a licensed medium (also referred to as the “licensed spectrum” and/or the “licensed band”) and an unlicensed shared medium (also referred to as the “unlicensed spectrum” and/or the “unlicensed band”) The licensed spectrum may include channels that operate in the frequency range of approximately 400 MHz to approximately 3.8 GHz, whereas the unlicensed spectrum may include the 5 GHz band.

To operate in the unlicensed spectrum, the UEs701and the RAN nodes711may operate using LAA, eLAA, and/or feLAA mechanisms. In these implementations, the UEs701and the RAN nodes711may perform one or more known medium-sensing operations and/or carrier-sensing operations in order to determine whether one or more channels in the unlicensed spectrum is unavailable or otherwise occupied prior to transmitting in the unlicensed spectrum. The medium/carrier sensing operations may be performed according to a listen-before-talk (LBT) protocol.

LBT is a mechanism whereby equipment (for example, UEs701RAN nodes711, etc.) senses a medium (for example, a channel or carrier frequency) and transmits when the medium is sensed to be idle (or when a specific channel in the medium is sensed to be unoccupied). The medium sensing operation may include CCA, which utilizes at least ED to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear. This LBT mechanism allows cellular/LAA networks to coexist with incumbent systems in the unlicensed spectrum and with other LAA networks. ED may include sensing RF energy across an intended transmission band for a period of time and comparing the sensed RF energy to a predefined or configured threshold.

Typically, the incumbent systems in the 5 GHz band are WLANs based on IEEE 802.11 technologies. WLAN employs a contention-based channel access mechanism, called CSMA/CA. Here, when a WLAN node (e.g., a mobile station (MS) such as UE701, AP706, or the like) intends to transmit, the WLAN node may first perform CCA before transmission. Additionally, a backoff mechanism is used to avoid collisions in situations where more than one WLAN node senses the channel as idle and transmits at the same time. The backoff mechanism may be a counter that is drawn randomly within the CWS, which is increased exponentially upon the occurrence of collision and reset to a minimum value when the transmission succeeds. The LBT mechanism designed for LAA is somewhat similar to the CSMA/CA of WLAN. In some implementations, the LBT procedure for DL or UL transmission bursts including PDSCH or PUSCH transmissions, respectively, may have an LAA contention window that is variable in length between X and Y ECCA slots, where X and Y are minimum and maximum values for the CWSs for LAA. In one example, the minimum CWS for an LAA transmission may be 9 microseconds (ms); however, the size of the CWS and a MCOT (for example, a transmission burst) may be based on governmental regulatory requirements.

The LAA mechanisms are built upon CA technologies of LTE-Advanced systems. In CA, each aggregated carrier is referred to as a CC. A CC may have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of five CCs can be aggregated, and therefore, a maximum aggregated bandwidth is 100 MHz. In FDD systems, the number of aggregated carriers can be different for DL and UL, where the number of UL CCs is equal to or lower than the number of DL component carriers. In some cases, individual CCs can have a different bandwidth than other CCs. In TDD systems, the number of CCs as well as the bandwidths of each CC is usually the same for DL and UL.

CA also comprises individual serving cells to provide individual CCs. The coverage of the serving cells may differ, for example, because CCs on different frequency bands will experience different pathloss. A primary service cell or PCell may provide a PCC for both UL and DL, and may handle RRC and NAS related activities. The other serving cells are referred to as SCells, and each SCell may provide an individual SCC for both UL and DL. The SCCs may be added and removed as required, while changing the PCC may require the UE701to undergo a handover. In LAA, eLAA, and feLAA, some or all of the SCells may operate in the unlicensed spectrum (referred to as “LAA SCells”), and the LAA SCells are assisted by a PCell operating in the licensed spectrum. When a UE is configured with more than one LAA SCell, the UE may receive UL grants on the configured LAA SCells indicating different PUSCH starting positions within a same subframe.

The PDSCH carries user data and higher-layer signaling to the UEs701. The PDCCH carries information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs701about the transport format, resource allocation, and HARQ information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE701bwithin a cell) may be performed at any of the RAN nodes711based on channel quality information fed back from any of the UEs701. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs701.

The RAN nodes711may be configured to communicate with one another via interface712. In embodiments where the system700is an LTE system (e.g., when CN720is an EPC820as inFIG. 8), the interface712may be an X2 interface712. The X2 interface may be defined between two or more RAN nodes711(e.g., two or more eNBs and the like) that connect to EPC720, and/or between two eNBs connecting to EPC720. In some implementations, the X2 interface may include an X2 user plane interface (X2-U) and an X2 control plane interface (X2-C). The X2-U may provide flow control mechanisms for user data packets transferred over the X2 interface, and may be used to communicate information about the delivery of user data between eNBs. For example, the X2-U may provide specific sequence number information for user data transferred from a MeNB to an SeNB; information about successful in sequence delivery of PDCP PDUs to a UE701from an SeNB for user data; information of PDCP PDUs that were not delivered to a UE701; information about a current minimum desired buffer size at the SeNB for transmitting to the UE user data; and the like. The X2-C may provide intra-LTE access mobility functionality, including context transfers from source to target eNBs, user plane transport control, etc.; load management functionality; as well as inter-cell interference coordination functionality.

In embodiments where the system700is a 5G or NR system (e.g., when CN720is an 5GC920as inFIG. 9), the interface712may be an Xn interface712. The Xn interface is defined between two or more RAN nodes711(e.g., two or more gNBs and the like) that connect to 5GC720, between a RAN node711(e.g., a gNB) connecting to 5GC720and an eNB, and/or between two eNBs connecting to 5GC720. In some implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functionality. The Xn-C may provide management and error handling functionality, functionality to manage the Xn-C interface; mobility support for UE701in a connected mode (e.g., CM-CONNECTED) including functionality to manage the UE mobility for connected mode between one or more RAN nodes711. The mobility support may include context transfer from an old (source) serving RAN node711to new (target) serving RAN node711; and control of user plane tunnels between old (source) serving RAN node711to new (target) serving RAN node711. A protocol stack of the Xn-U may include a transport network layer built on Internet Protocol (IP) transport layer, and a GTP-U layer on top of a UDP and/or IP layer(s) to carry user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol (referred to as Xn Application Protocol (Xn-AP)) and a transport network layer that is built on SCTP. The SCTP may be on top of an IP layer, and may provide the guaranteed delivery of application layer messages. In the transport IP layer, point-to-point transmission is used to deliver the signaling PDUs. In other implementations, the Xn-U protocol stack and/or the Xn-C protocol stack may be same or similar to the user plane and/or control plane protocol stack(s) shown and described herein.

The RAN710is shown to be communicatively coupled to a core network—in this embodiment, core network (CN)720. The CN720may comprise a plurality of network elements722, which are configured to offer various data and telecommunications services to customers/subscribers (e.g., users of UEs701) who are connected to the CN720via the RAN710. The components of the CN720may be implemented in one physical node or separate physical nodes including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some embodiments, NFV may be utilized to virtualize any or all of the above-described network node functions via executable instructions stored in one or more computer-readable storage mediums (described in further detail below). A logical instantiation of the CN720may be referred to as a network slice, and a logical instantiation of a portion of the CN720may be referred to as a network sub-slice. NFV architectures and infrastructures may be used to virtualize one or more network functions, alternatively performed by proprietary hardware, onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches. In other words, NFV systems can be used to execute virtual or reconfigurable implementations of one or more EPC components/functions.

Generally, the application server730may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS PS domain, LTE PS data services, etc.). The application server730can also be configured to support one or more communication services (e.g., VoIP sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs701via the EPC720.

In embodiments, the CN720may be a 5GC (referred to as “5GC720” or the like), and the RAN710may be connected with the CN720via an NG interface713. In embodiments, the NG interface713may be split into two parts, an NG user plane (NG-U) interface714, which carries traffic data between the RAN nodes711and a UPF, and the S1 control plane (NG-C) interface715, which is a signaling interface between the RAN nodes711and AMFs. Embodiments where the CN720is a 5GC720are discussed in more detail with regard toFIG. 9.

In embodiments, the CN720may be a 5G CN (referred to as “5GC720” or the like), while in other embodiments, the CN720may be an EPC). Where CN720is an EPC (referred to as “EPC720” or the like), the RAN710may be connected with the CN720via an S1 interface713. In embodiments, the S1 interface713may be split into two parts, an S1 user plane (S1-U) interface714, which carries traffic data between the RAN nodes711and the S-GW, and the S1-MME interface715, which is a signaling interface between the RAN nodes711and MMEs.

FIG. 8illustrates an example architecture of a system800including a first CN820, in accordance with various embodiments. In this example, system800may implement the LTE standard wherein the CN820is an EPC820that corresponds with CN720ofFIG. 7. Additionally, the UE801may be the same or similar as the UEs701ofFIG. 7, and the E-UTRAN810may be a RAN that is the same or similar to the RAN710ofFIG. 7, and which may include RAN nodes711discussed previously. The CN820may comprise MMEs821, an S-GW822, a P-GW823, a HSS824, and a SGSN825.

The MMEs821may be similar in function to the control plane of legacy SGSN, and may implement MM functions to keep track of the current location of a UE801. The MMEs821may perform various MM procedures to manage mobility aspects in access such as gateway selection and tracking area list management. MM (also referred to as “EPS MW” or “EMM” in E-UTRAN systems) may refer to all applicable procedures, methods, data storage, etc. that are used to maintain knowledge about a present location of the UE801, provide user identity confidentiality, and/or perform other like services to users/subscribers. Each UE801and the MME821may include an MM or EMM sublayer, and an MM context may be established in the UE801and the MME821when an attach procedure is successfully completed. The MM context may be a data structure or database object that stores MM-related information of the UE801. The MMEs821may be coupled with the HSS824via an S6a reference point, coupled with the SGSN825via an S3 reference point, and coupled with the S-GW822via an S11 reference point.

The SGSN825may be a node that serves the UE801by tracking the location of an individual UE801and performing security functions. In addition, the SGSN825may perform Inter-EPC node signaling for mobility between 2G/3G and E-UTRAN 3GPP access networks; PDN and S-GW selection as specified by the MMEs821; handling of UE801time zone functions as specified by the MMEs821; and MME selection for handovers to E-UTRAN 3GPP access network. The S3 reference point between the MMEs821and the SGSN825may enable user and bearer information exchange for inter-3GPP access network mobility in idle and/or active states.

The HSS824may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The EPC820may comprise one or several HSSs824, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS824can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc. An S6a reference point between the HSS824and the MMEs821may enable transfer of subscription and authentication data for authenticating/authorizing user access to the EPC820between HSS824and the MMEs821.

The S-GW822may terminate the S1 interface713(“S1-U” inFIG. 8) toward the RAN810, and routes data packets between the RAN810and the EPC820. In addition, the S-GW822may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. The S11 reference point between the S-GW822and the MMEs821may provide a control plane between the MMEs821and the S-GW822. The S-GW822may be coupled with the P-GW823via an S5 reference point.

The P-GW823may terminate an SGi interface toward a PDN830. The P-GW823may route data packets between the EPC820and external networks such as a network including the application server730(alternatively referred to as an “AF”) via an IP interface725(see e.g.,FIG. 7). In embodiments, the P-GW823may be communicatively coupled to an application server (application server730ofFIG. 7or PDN830inFIG. 8) via an IP communications interface725(see, e.g.,FIG. 7). The S5 reference point between the P-GW823and the S-GW822may provide user plane tunneling and tunnel management between the P-GW823and the S-GW822. The S5 reference point may also be used for S-GW822relocation due to UE801mobility and if the S-GW822needs to connect to a non-collocated P-GW823for the required PDN connectivity. The P-GW823may further include a node for policy enforcement and charging data collection (e.g., PCEF (not shown)). Additionally, the SGi reference point between the P-GW823and the packet data network (PDN)830may be an operator external public, a private PDN, or an intra operator packet data network, for example, for provision of IMS services. The P-GW823may be coupled with a PCRF826via a Gx reference point.

PCRF826is the policy and charging control element of the EPC820. In a non-roaming scenario, there may be a single PCRF826in the Home Public Land Mobile Network (HPLMN) associated with a UE801's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE801's IP-CAN session, a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF826may be communicatively coupled to the application server830via the P-GW823. The application server830may signal the PCRF826to indicate a new service flow and select the appropriate QoS and charging parameters. The PCRF826may provision this rule into a PCEF (not shown) with the appropriate TFT and QCI, which commences the QoS and charging as specified by the application server830. The Gx reference point between the PCRF826and the P-GW823may allow for the transfer of QoS policy and charging rules from the PCRF826to PCEF in the P-GW823. An Rx reference point may reside between the PDN830(or “AF830”) and the PCRF826.

FIG. 9illustrates an architecture of a system900including a second CN920in accordance with various embodiments. The system900is shown to include a UE901, which may be the same or similar to the UEs701and UE801discussed previously; a (R)AN910, which may be the same or similar to the RAN710and RAN810discussed previously, and which may include RAN nodes711discussed previously; and a DN903, which may be, for example, operator services, Internet access or 3rd party services; and a 5GC920. The 5GC920may include an AUSF922; an AMF921; a SMF924; a NEF923; a PCF926; a NRF925; a UDM927; an AF928; a UPF902; and a NSSF929.

The UPF902may act as an anchor point for intra-RAT and inter-RAT mobility, an external PDU session point of interconnect to DN903, and a branching point to support multi-homed PDU session. The UPF902may also perform packet routing and forwarding, perform packet inspection, enforce the user plane part of policy rules, lawfully intercept packets (UP collection), perform traffic usage reporting, perform QoS handling for a user plane (e.g., packet filtering, gating, UL/DL rate enforcement), perform Uplink Traffic verification (e.g., SDF to QoS flow mapping), transport level packet marking in the uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. UPF902may include an uplink classifier to support routing traffic flows to a data network. The DN903may represent various network operator services, Internet access, or third party services. DN903may include, or be similar to, application server730discussed previously. The UPF902may interact with the SMF924via an N4 reference point between the SMF924and the UPF902.

The AUSF922may store data for authentication of UE901and handle authentication-related functionality. The AUSF922may facilitate a common authentication framework for various access types. The AUSF922may communicate with the AMF921via an N12 reference point between the AMF921and the AUSF922; and may communicate with the UDM927via an N13 reference point between the UDM927and the AUSF922. Additionally, the AUSF922may exhibit an Nausf service-based interface.

The AMF921may be responsible for registration management (e.g., for registering UE901, etc.), connection management, reachability management, mobility management, and lawful interception of AMF-related events, and access authentication and authorization. The AMF921may be a termination point for the an N11 reference point between the AMF921and the SMF924. The AMF921may provide transport for SM messages between the UE901and the SMF924, and act as a transparent proxy for routing SM messages. AMF921may also provide transport for SMS messages between UE901and an SMSF (not shown byFIG. 9). AMF921may act as SEAF, which may include interaction with the AUSF922and the UE901, receipt of an intermediate key that was established as a result of the UE901authentication process. Where USIM based authentication is used, the AMF921may retrieve the security material from the AUSF922. AMF921may also include a SCM function, which receives a key from the SEA that it uses to derive access-network specific keys. Furthermore, AMF921may be a termination point of a RAN CP interface, which may include or be an N2 reference point between the (R)AN910and the AMF921; and the AMF921may be a termination point of NAS (N1) signalling, and perform NAS ciphering and integrity protection.

AMF921may also support NAS signalling with a UE901over an N3 IWF interface. The N3IWF may be used to provide access to untrusted entities. N3IWF may be a termination point for the N2 interface between the (R)AN910and the AMF921for the control plane, and may be a termination point for the N3 reference point between the (R)AN910and the UPF902for the user plane. As such, the AMF921may handle N2 signalling from the SMF924and the AMF921for PDU sessions and QoS, encapsulate/de-encapsulate packets for IPSec and N3 tunneling, mark N3 user-plane packets in the uplink, and enforce QoS corresponding to N3 packet marking taking into account QoS requirements associated with such marking received over N2. N3IWF may also relay uplink and downlink control-plane NAS signalling between the UE901and AMF921via an N1 reference point between the UE901and the AMF921, and relay uplink and downlink user-plane packets between the UE901and UPF902. The N3IWF also provides mechanisms for IPsec tunnel establishment with the UE901. The AMF921may exhibit an Namf service-based interface, and may be a termination point for an N14 reference point between two AMFs921and an N17 reference point between the AMF921and a 5G-EIR (not shown byFIG. 9).

The UE901may need to register with the AMF921in order to receive network services. RM is used to register or deregister the UE901with the network (e.g., AMF921), and establish a UE context in the network (e.g., AMF921). The UE901may operate in an RM-REGISTERED state or an RM-DEREGISTERED state. In the RM DEREGISTERED state, the UE901is not registered with the network, and the UE context in AMF921holds no valid location or routing information for the UE901so the UE901is not reachable by the AMF921. In the RM REGISTERED state, the UE901is registered with the network, and the UE context in AMF921may hold a valid location or routing information for the UE901so the UE901is reachable by the AMF921. In the RM-REGISTERED state, the UE901may perform mobility Registration Update procedures, perform periodic Registration Update procedures triggered by expiration of the periodic update timer (e.g., to notify the network that the UE901is still active), and perform a Registration Update procedure to update UE capability information or to re-negotiate protocol parameters with the network, among others.

The AMF921may store one or more RM contexts for the UE901, where each RM context is associated with a specific access to the network. The RM context may be a data structure, database object, etc. that indicates or stores, inter alia, a registration state per access type and the periodic update timer. The AMF921may also store a 5GC MM context that may be the same or similar to the (E)MM context discussed previously. In various embodiments, the AMF921may store a CE mode B Restriction parameter of the UE901in an associated MM context or RM context. The AMF921may also derive the value, when needed, from the UE's usage setting parameter already stored in the UE context (and/or MM/RM context).

CM may be used to establish and release a signaling connection between the UE901and the AMF921over the N1 interface. The signaling connection is used to enable NAS signaling exchange between the UE901and the CN920, and comprises both the signaling connection between the UE and the AN (e.g., RRC connection or UE-N3IWF connection for non-3GPP access) and the N2 connection for the UE901between the AN (e.g., RAN910) and the AMF921. The UE901may operate in one of two CM states, CM-IDLE mode or CM-CONNECTED mode. When the UE901is operating in the CM-IDLE state/mode, the UE901may have no NAS signaling connection established with the AMF921over the N1 interface, and there may be (R)AN910signaling connection (e.g., N2 and/or N3 connections) for the UE901. When the UE901is operating in the CM-CONNECTED state/mode, the UE901may have an established NAS signaling connection with the AMF921over the N1 interface, and there may be a (R)AN910signaling connection (e.g., N2 and/or N3 connections) for the UE901. Establishment of an N2 connection between the (R)AN910and the AMF921may cause the UE901to transition from CM-IDLE mode to CM-CONNECTED mode, and the UE901may transition from the CM-CONNECTED mode to the CM-IDLE mode when N2 signaling between the (R)AN910and the AMF921is released.

The SMF924may be responsible for SM (e.g., session establishment, modify and release, including tunnel maintain between UPF and AN node); UE IP address allocation and management (including optional authorization); selection and control of UP function; configuring traffic steering at UPF to route traffic to proper destination; termination of interfaces toward policy control functions; controlling part of policy enforcement and QoS; lawful intercept (for SM events and interface to LI system); termination of SM parts of NAS messages; downlink data notification; initiating AN specific SM information, sent via AMF over N2 to AN, and determining SSC mode of a session. SM may refer to management of a PDU session, and a PDU session or “session” may refer to a PDU connectivity service that provides or enables the exchange of PDUs between a UE901and a data network (DN)903identified by a Data Network Name (DNN). PDU sessions may be established upon UE901request, modified upon UE901and 5GC920request, and released upon UE901and 5GC920request using NAS SM signaling exchanged over the N1 reference point between the UE901and the SMF924. Upon request from an application server, the 5GC920may trigger a specific application in the UE901. In response to receipt of the trigger message, the UE901may pass the trigger message (or relevant parts/information of the trigger message) to one or more identified applications in the UE901. The identified application(s) in the UE901may establish a PDU session to a specific DNN. The SMF924may check whether the UE901requests are compliant with user subscription information associated with the UE901. In this regard, the SMF924may retrieve and/or request to receive update notifications on SMF924level subscription data from the UDM927.

The SMF924may include the following roaming functionality: handling local enforcement to apply QoS SLAs (VPLMN); charging data collection and charging interface (VPLMN); lawful intercept (in VPLMN for SM events and interface to LI system); and support for interaction with external DN for transport of signalling for PDU session authorization/authentication by external DN. An N16 reference point between two SMFs924may be included in the system900, which may be between another SMF924in a visited network and the SMF924in the home network in roaming scenarios. Additionally, the SMF924may exhibit the Nsmf service-based interface.

The NEF923may provide means for securely exposing the services and capabilities provided by 3GPP network functions for third party, internal exposure/re-exposure, Application Functions (e.g., AF928), edge computing or fog computing systems, etc. In such embodiments, the NEF923may authenticate, authorize, and/or throttle the AFs. NEF923may also translate information exchanged with the AF928and information exchanged with internal network functions. For example, the NEF923may translate between an AF-Service-Identifier and an internal 5GC information. NEF923may also receive information from other network functions (NFs) based on exposed capabilities of other network functions. This information may be stored at the NEF923as structured data, or at a data storage NF using standardized interfaces. The stored information can then be re-exposed by the NEF923to other NFs and AFs, and/or used for other purposes such as analytics. Additionally, the NEF923may exhibit an Nnef service-based interface.

The NRF925may support service discovery functions, receive NF discovery requests from NF instances, and provide the information of the discovered NF instances to the NF instances. NRF925also maintains information of available NF instances and their supported services. As used herein, the terms “instantiate,” “instantiation,” and the like may refer to the creation of an instance, and an “instance” may refer to a concrete occurrence of an object, which may occur, for example, during execution of program code. Additionally, the NRF925may exhibit the Nnrf service-based interface.

The PCF926may provide policy rules to control plane function(s) to enforce them, and may also support unified policy framework to govern network behaviour. The PCF926may also implement an FE to access subscription information relevant for policy decisions in a UDR of the UDM927. The PCF926may communicate with the AMF921via an N15 reference point between the PCF926and the AMF921, which may include a PCF926in a visited network and the AMF921in case of roaming scenarios. The PCF926may communicate with the AF928via an N5 reference point between the PCF926and the AF928; and with the SMF924via an N7 reference point between the PCF926and the SMF924. The system900and/or CN920may also include an N24 reference point between the PCF926(in the home network) and a PCF926in a visited network. Additionally, the PCF926may exhibit an Npcf service-based interface.

The UDM927may handle subscription-related information to support the network entities' handling of communication sessions, and may store subscription data of UE901. For example, subscription data may be communicated between the UDM927and the AMF921via an N8 reference point between the UDM927and the AMF. The UDM927may include two parts, an application FE and a UDR (the FE and UDR are not shown byFIG. 9). The UDR may store subscription data and policy data for the UDM927and the PCF926, and/or structured data for exposure and application data (including PFDs for application detection, application request information for multiple UEs901) for the NEF923. The Nudr service-based interface may be exhibited by the UDR221to allow the UDM927, PCF926, and NEF923to access a particular set of the stored data, as well as to read, update (e.g., add, modify), delete, and subscribe to notification of relevant data changes in the UDR. The UDM may include a UDM-FE, which is in charge of processing credentials, location management, subscription management and so on. Several different front ends may serve the same user in different transactions. The UDM-FE accesses subscription information stored in the UDR and performs authentication credential processing, user identification handling, access authorization, registration/mobility management, and subscription management. The UDR may interact with the SMF924via an N10 reference point between the UDM927and the SMF924. UDM927may also support SMS management, wherein an SMS-FE implements the similar application logic as discussed previously. Additionally, the UDM927may exhibit the Nudm service-based interface.

The AF928may provide application influence on traffic routing, provide access to the NCE, and interact with the policy framework for policy control. The NCE may be a mechanism that allows the 5GC920and AF928to provide information to each other via NEF923, which may be used for edge computing implementations. In such implementations, the network operator and third party services may be hosted close to the UE901access point of attachment to achieve an efficient service delivery through the reduced end-to-end latency and load on the transport network. For edge computing implementations, the 5GC may select a UPF902close to the UE901and execute traffic steering from the UPF902to DN903via the N6 interface. This may be based on the UE subscription data, UE location, and information provided by the AF928. In this way, the AF928may influence UPF (re)selection and traffic routing. Based on operator deployment, when AF928is considered to be a trusted entity, the network operator may permit AF928to interact directly with relevant NFs. Additionally, the AF928may exhibit an Naf service-based interface.

The NSSF929may select a set of network slice instances serving the UE901. The NSSF929may also determine allowed NSSAI and the mapping to the subscribed S-NSSAIs, if needed. The NSSF929may also determine the AMF set to be used to serve the UE901, or a list of candidate AMF(s)921based on a suitable configuration and possibly by querying the NRF925. The selection of a set of network slice instances for the UE901may be triggered by the AMF921with which the UE901is registered by interacting with the NSSF929, which may lead to a change of AMF921. The NSSF929may interact with the AMF921via an N22 reference point between AMF921and NSSF929; and may communicate with another NSSF929in a visited network via an N31 reference point (not shown byFIG. 9). Additionally, the NSSF929may exhibit an Nnssf service-based interface.

As discussed previously, the CN920may include an SMSF, which may be responsible for SMS subscription checking and verification, and relaying SM messages to/from the UE901to/from other entities, such as an SMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF921and UDM927for a notification procedure that the UE901is available for SMS transfer (e.g., set a UE not reachable flag, and notifying UDM927when UE901is available for SMS).

The CN120may also include other elements that are not shown byFIG. 9, such as a Data Storage system/architecture, a 5G-EIR, a SEPP, and the like. The Data Storage system may include a SDSF, an UDSF, and/or the like. Any NF may store and retrieve unstructured data into/from the UDSF (e.g., UE contexts), via N18 reference point between any NF and the UDSF (not shown byFIG. 9). Individual NFs may share a UDSF for storing their respective unstructured data or individual NFs may each have their own UDSF located at or near the individual NFs. Additionally, the UDSF may exhibit an Nudsf service-based interface (not shown byFIG. 9). The 5G-EIR may be an NF that checks the status of PEI for determining whether particular equipment/entities are blacklisted from the network; and the SEPP may be a non-transparent proxy that performs topology hiding, message filtering, and policing on inter-PLMN control plane interfaces.

Additionally, there may be many more reference points and/or service-based interfaces between the NF services in the NFs; however, these interfaces and reference points have been omitted fromFIG. 9for clarity. In one example, the CN920may include an Nx interface, which is an inter-CN interface between the MME (e.g., MME821) and the AMF921in order to enable interworking between CN920and CN820. Other example interfaces/reference points may include an N5g-EIR service-based interface exhibited by a 5G-EIR, an N27 reference point between the NRF in the visited network and the NRF in the home network; and an N31 reference point between the NSSF in the visited network and the NSSF in the home network.

FIG. 10illustrates an example of infrastructure equipment1000in accordance with various embodiments. The infrastructure equipment1000(or “system1000”) may be implemented as a base station, radio head, RAN node such as the RAN nodes711and/or AP706shown and described previously, application server(s)730, and/or any other element/device discussed herein. In other examples, the system1000could be implemented in or by a UE.

The system1000includes application circuitry1005, baseband circuitry1010, one or more radio front end modules (RFEMs)1015, memory circuitry1020, power management integrated circuitry (PMIC)1025, power tee circuitry1030, network controller circuitry1035, network interface connector1040, satellite positioning circuitry1045, and user interface1050. In some embodiments, the device1000may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device. For example, said circuitries may be separately included in more than one device for CRAN, vBBU, or other like implementations.

In some implementations, the application circuitry1005may include one or more hardware accelerators, which may be microprocessors, programmable processing devices, or the like. The one or more hardware accelerators may include, for example, computer vision (CV) and/or deep learning (DL) accelerators. As examples, the programmable processing devices may be one or more a field-programmable devices (FPDs) such as field-programmable gate arrays (FPGAs) and the like; programmable logic devices (PLDs) such as complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), and the like; ASICs such as structured ASICs and the like; programmable SoCs (PSoCs); and the like. In such implementations, the circuitry of application circuitry1005may comprise logic blocks or logic fabric, and other interconnected resources that may be programmed to perform various functions, such as the procedures, methods, functions, etc. of the various embodiments discussed herein. In such embodiments, the circuitry of application circuitry1005may include memory cells (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., static random access memory (SRAM), anti-fuses, etc.)) used to store logic blocks, logic fabric, data, etc. in look-up-tables (LUTs) and the like.

The baseband circuitry1010may be implemented, for example, as a solder-down substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board or a multi-chip module containing two or more integrated circuits. The various hardware electronic elements of baseband circuitry1010are discussed infra with regard toFIG. 12.

The PMIC1025may include voltage regulators, surge protectors, power alarm detection circuitry, and one or more backup power sources such as a battery or capacitor. The power alarm detection circuitry may detect one or more of brown out (under-voltage) and surge (over-voltage) conditions. The power tee circuitry1030may provide for electrical power drawn from a network cable to provide both power supply and data connectivity to the infrastructure equipment1000using a single cable.

The network controller circuitry1035may provide connectivity to a network using a standard network interface protocol such as Ethernet, Ethernet over GRE Tunnels, Ethernet over Multiprotocol Label Switching (MPLS), or some other suitable protocol. Network connectivity may be provided to/from the infrastructure equipment1000via network interface connector1040using a physical connection, which may be electrical (commonly referred to as a “copper interconnect”), optical, or wireless. The network controller circuitry1035may include one or more dedicated processors and/or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the network controller circuitry1035may include multiple controllers to provide connectivity to other networks using the same or different protocols.

The positioning circuitry1045includes circuitry to receive and decode signals transmitted/broadcasted by a positioning network of a global navigation satellite system (GNSS). Examples of navigation satellite constellations (or GNSS) include United States' Global Positioning System (GPS), Russia's Global Navigation System (GLONASS), the European Union's Galileo system, China's BeiDou Navigation Satellite System, a regional navigation system or GNSS augmentation system (e.g., Navigation with Indian Constellation (NAVIC), Japan's Quasi-Zenith Satellite System (QZSS), France's Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS), etc.), or the like. The positioning circuitry1045comprises various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, and the like to facilitate OTA communications) to communicate with components of a positioning network, such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry1045may include a Micro-Technology for Positioning, Navigation, and Timing (Micro-PNT) IC that uses a master timing clock to perform position tracking/estimation without GNSS assistance. The positioning circuitry1045may also be part of, or interact with, the baseband circuitry1010and/or RFEMs1015to communicate with the nodes and components of the positioning network. The positioning circuitry1045may also provide position data and/or time data to the application circuitry1005, which may use the data to synchronize operations with various infrastructure (e.g., RAN nodes711, etc.), or the like.

The components shown byFIG. 10may communicate with one another using interface circuitry, which may include any number of bus and/or interconnect (IX) technologies such as industry standard architecture (ISA), extended ISA (EISA), peripheral component interconnect (PCI), peripheral component interconnect extended (PCIx), PCI express (PCIe), or any number of other technologies. The bus/IX may be a proprietary bus, for example, used in a SoC based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, point to point interfaces, and a power bus, among others.

FIG. 11illustrates an example of a platform1100(or “device1100”) in accordance with various embodiments. In embodiments, the computer platform1100may be suitable for use as UEs701,801,901, application servers730, and/or any other element/device discussed herein. The platform1100may include any combinations of the components shown in the example. The components of platform1100may be implemented as integrated circuits (ICs), portions thereof, discrete electronic devices, or other modules, logic, hardware, software, firmware, or a combination thereof adapted in the computer platform1100, or as components otherwise incorporated within a chassis of a larger system. The block diagram ofFIG. 11is intended to show a high level view of components of the computer platform1100. However, some of the components shown may be omitted, additional components may be present, and different arrangement of the components shown may occur in other implementations.

The processor(s) of application circuitry1005may include, for example, one or more processor cores, one or more application processors, one or more GPUs, one or more RISC processors, one or more ARM processors, one or more CISC processors, one or more DSP, one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, a multithreaded processor, an ultra-low voltage processor, an embedded processor, some other known processing element, or any suitable combination thereof. In some embodiments, the application circuitry1005may comprise, or may be, a special-purpose processor/controller to operate according to the various embodiments herein.

As examples, the processor(s) of application circuitry1105may include an Apple A-series processor. The processors of the application circuitry1105may also be one or more of Intel® Architecture Core™ based processor, such as a Quark™, an Atom™, an i3, an i5, an i7, or an MCU-class processor, or another such processor available from Intel® Corporation, Santa Clara, Calif.; Advanced Micro Devices (AMD) Ryzen® processor(s) or Accelerated Processing Units (APUs); Snapdragon™ processor(s) from Qualcomm® Technologies, Inc., Texas Instruments, Inc.® Open Multimedia Applications Platform (OMAP)™ processor(s); a MIPS-based design from MIPS Technologies, Inc. such as MIPS Warrior M-class, Warrior I-class, and Warrior P-class processors; an ARM-based design licensed from ARM Holdings, Ltd., such as the ARM Cortex-A, Cortex-R, and Cortex-M family of processors; or the like. In some implementations, the application circuitry1105may be a part of a system on a chip (SoC) in which the application circuitry1105and other components are formed into a single integrated circuit.

The baseband circuitry1110may be implemented, for example, as a solder-down substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board or a multi-chip module containing two or more integrated circuits. The various hardware electronic elements of baseband circuitry1110are discussed infra with regard toFIG. 12.

The memory circuitry1120may include any number and type of memory devices used to provide for a given amount of system memory. As examples, the memory circuitry1120may include one or more of volatile memory including random access memory (RAM), dynamic RAM (DRAM) and/or synchronous dynamic RAM (SDRAM), and nonvolatile memory (NVM) including high-speed electrically erasable memory (commonly referred to as Flash memory), phase change random access memory (PRAM), magnetoresistive random access memory (MRAM), etc. The memory circuitry1120may be developed in accordance with a Joint Electron Devices Engineering Council (JEDEC) low power double data rate (LPDDR)-based design, such as LPDDR2, LPDDR3, LPDDR4, or the like. Memory circuitry1120may be implemented as one or more of solder down packaged integrated circuits, single die package (SDP), dual die package (DDP) or quad die package (Q17P), socketed memory modules, dual inline memory modules (DIMMs) including microDIMMs or MiniDIMMs, and/or soldered onto a motherboard via a ball grid array (BGA). In low power implementations, the memory circuitry1120may be on-die memory or registers associated with the application circuitry1105. To provide for persistent storage of information such as data, applications, operating systems and so forth, memory circuitry1120may include one or more mass storage devices, which may include, inter alia, a solid state disk drive (SSDD), hard disk drive (HDD), a micro HDD, resistance change memories, phase change memories, holographic memories, or chemical memories, among others. For example, the computer platform1100may incorporate the three-dimensional (3D) cross-point (XPOINT) memories from Intel® and Micron®.

Removable memory circuitry1123may include devices, circuitry, enclosures/housings, ports or receptacles, etc. used to couple portable data storage devices with the platform1100. These portable data storage devices may be used for mass storage purposes, and may include, for example, flash memory cards (e.g., Secure Digital (SD) cards, microSD cards, xD picture cards, and the like), and USB flash drives, optical discs, external HDDs, and the like.

The platform1100may also include interface circuitry (not shown) that is used to connect external devices with the platform1100. The external devices connected to the platform1100via the interface circuitry include sensor circuitry1121and electro-mechanical components (EMCs)1122, as well as removable memory devices coupled to removable memory circuitry1123.

The sensor circuitry1121include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other a device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units (IMUs) comprising accelerometers, gyroscopes, and/or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) comprising 3-axis accelerometers, 3-axis gyroscopes, and/or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless apertures); light detection and ranging (LiDAR) sensors; proximity sensors (e.g., infrared radiation detector and the like), depth sensors, ambient light sensors, ultrasonic transceivers; microphones or other like audio capture devices; etc.

EMCs1122include devices, modules, or subsystems whose purpose is to enable platform1100to change its state, position, and/or orientation, or move or control a mechanism or (sub)system. Additionally, EMCs1122may be configured to generate and send messages/signalling to other components of the platform1100to indicate a current state of the EMCs1122. Examples of the EMCs1122include one or more power switches, relays including electromechanical relays (EMRs) and/or solid state relays (SSRs), actuators (e.g., valve actuators, etc.), an audible sound generator, a visual warning device, motors (e.g., DC motors, stepper motors, etc.), wheels, thrusters, propellers, claws, clamps, hooks, and/or other like electro-mechanical components. In embodiments, platform1100is configured to operate one or more EMCs1122based on one or more captured events and/or instructions or control signals received from a service provider and/or various clients.

In some implementations, the interface circuitry may connect the platform1100with positioning circuitry1145. The positioning circuitry1145includes circuitry to receive and decode signals transmitted/broadcasted by a positioning network of a GNSS. Examples of navigation satellite constellations (or GNSS) include United States' GPS, Russia's GLONASS, the European Union's Galileo system, China's BeiDou Navigation Satellite System, a regional navigation system or GNSS augmentation system (e.g., NAVIC), Japan's QZSS, France's DORIS, etc.), or the like. The positioning circuitry1145comprises various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, and the like to facilitate OTA communications) to communicate with components of a positioning network, such as navigation satellite constellation nodes. In some embodiments, the positioning circuitry1145may include a Micro-PNT IC that uses a master timing clock to perform position tracking/estimation without GNSS assistance. The positioning circuitry1145may also be part of, or interact with, the baseband circuitry1010and/or RFEMs1115to communicate with the nodes and components of the positioning network. The positioning circuitry1145may also provide position data and/or time data to the application circuitry1105, which may use the data to synchronize operations with various infrastructure (e.g., radio base stations), for turn-by-turn navigation applications, or the like

In some implementations, the interface circuitry may connect the platform1100with Near-Field Communication (NFC) circuitry1140. NFC circuitry1140is configured to provide contactless, short-range communications based on radio frequency identification (RFID) standards, wherein magnetic field induction is used to enable communication between NFC circuitry1140and NFC-enabled devices external to the platform1100(e.g., an “NFC touchpoint”). NFC circuitry1140comprises an NFC controller coupled with an antenna element and a processor coupled with the NFC controller. The NFC controller may be a chip/IC providing NFC functionalities to the NFC circuitry1140by executing NFC controller firmware and an NFC stack. The NFC stack may be executed by the processor to control the NFC controller, and the NFC controller firmware may be executed by the NFC controller to control the antenna element to emit short-range RF signals. The RF signals may power a passive NFC tag (e.g., a microchip embedded in a sticker or wristband) to transmit stored data to the NFC circuitry1140, or initiate data transfer between the NFC circuitry1140and another active NFC device (e.g., a smartphone or an NFC-enabled POS terminal) that is proximate to the platform1100.

The driver circuitry1146may include software and hardware elements that operate to control particular devices that are embedded in the platform1100, attached to the platform1100, or otherwise communicatively coupled with the platform1100. The driver circuitry1146may include individual drivers allowing other components of the platform1100to interact with or control various input/output (I/O) devices that may be present within, or connected to, the platform1100. For example, driver circuitry1146may include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface of the platform1100, sensor drivers to obtain sensor readings of sensor circuitry1121and control and allow access to sensor circuitry1121, EMC drivers to obtain actuator positions of the EMCs1122and/or control and allow access to the EMCs1122, a camera driver to control and allow access to an embedded image capture device, audio drivers to control and allow access to one or more audio devices.

The power management integrated circuitry (PMIC)1125(also referred to as “power management circuitry1125”) may manage power provided to various components of the platform1100. In particular, with respect to the baseband circuitry1110, the PMIC1125may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMIC1125may often be included when the platform1100is capable of being powered by a battery1130, for example, when the device is included in a UE701,801,901.

A battery1130may power the platform1100, although in some examples the platform1100may be mounted deployed in a fixed location, and may have a power supply coupled to an electrical grid. The battery1130may be a lithium ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in V2X applications, the battery1130may be a typical lead-acid automotive battery.

In some implementations, the battery1130may be a “smart battery,” which includes or is coupled with a Battery Management System (BMS) or battery monitoring integrated circuitry. The BMS may be included in the platform1100to track the state of charge (SoCh) of the battery1130. The BMS may be used to monitor other parameters of the battery1130to provide failure predictions, such as the state of health (SoH) and the state of function (SoF) of the battery1130. The BMS may communicate the information of the battery1130to the application circuitry1105or other components of the platform1100. The BMS may also include an analog-to-digital (ADC) convertor that allows the application circuitry1105to directly monitor the voltage of the battery1130or the current flow from the battery1130. The battery parameters may be used to determine actions that the platform1100may perform, such as transmission frequency, network operation, sensing frequency, and the like.

A power block, or other power supply coupled to an electrical grid may be coupled with the BMS to charge the battery1130. In some examples, the power block XS30 may be replaced with a wireless power receiver to obtain the power wirelessly, for example, through a loop antenna in the computer platform1100. In these examples, a wireless battery charging circuit may be included in the BMS. The specific charging circuits chosen may depend on the size of the battery1130, and thus, the current required. The charging may be performed using the Airfuel standard promulgated by the Airfuel Alliance, the Qi wireless charging standard promulgated by the Wireless Power Consortium, or the Rezence charging standard promulgated by the Alliance for Wireless Power, among others.

User interface circuitry1150includes various input/output (I/O) devices present within, or connected to, the platform1100, and includes one or more user interfaces designed to enable user interaction with the platform1100and/or peripheral component interfaces designed to enable peripheral component interaction with the platform1100. The user interface circuitry1150includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting an input including, inter alia, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphones, scanner, headset, and/or the like. The output device circuitry includes any physical or virtual means for showing information or otherwise conveying information, such as sensor readings, actuator position(s), or other like information. Output device circuitry may include any number and/or combinations of audio or visual display, including, inter alia, one or more simple visual outputs/indicators (e.g., binary status indicators (e.g., light emitting diodes (LEDs)) and multi-character visual outputs, or more complex outputs such as display devices or touchscreens (e.g., Liquid Chrystal Displays (LCD), LED displays, quantum dot displays, projectors, etc.), with the output of characters, graphics, multimedia objects, and the like being generated or produced from the operation of the platform1100. The output device circuitry may also include speakers or other audio emitting devices, printer(s), and/or the like. In some embodiments, the sensor circuitry1121may be used as the input device circuitry (e.g., an image capture device, motion capture device, or the like) and one or more EMCs may be used as the output device circuitry (e.g., an actuator to provide haptic feedback or the like). In another example, NFC circuitry comprising an NFC controller coupled with an antenna element and a processing device may be included to read electronic tags and/or connect with another NFC-enabled device. Peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a USB port, an audio jack, a power supply interface, etc.

Although not shown, the components of platform1100may communicate with one another using a suitable bus or interconnect (IX) technology, which may include any number of technologies, including ISA, EISA, PCI, PCIx, PCIe, a Time-Trigger Protocol (TTP) system, a FlexRay system, or any number of other technologies. The bus/IX may be a proprietary bus/IX, for example, used in a SoC based system. Other bus/IX systems may be included, such as an I2C interface, an SPI interface, point-to-point interfaces, and a power bus, among others.

FIG. 12illustrates example components of baseband circuitry1210and radio front end modules (RFEM)1215in accordance with various embodiments. The baseband circuitry1210corresponds to the baseband circuitry1010and1110ofFIGS. 10 and 11, respectively. The RFEM1215corresponds to the RFEM1015and1115ofFIGS. 10 and 11, respectively. As shown, the RFEMs1215may include Radio Frequency (RF) circuitry1206, front-end module (FEM) circuitry1208, antenna array1211coupled together at least as shown.

The baseband circuitry1210includes circuitry and/or control logic configured to carry out various radio/network protocol and radio control functions that enable communication with one or more radio networks via the RF circuitry1206. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry1210may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry1210may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments. The baseband circuitry1210is configured to process baseband signals received from a receive signal path of the RF circuitry1206and to generate baseband signals for a transmit signal path of the RF circuitry1206. The baseband circuitry1210is configured to interface with application circuitry1005/1105(seeFIGS. 10 and 11) for generation and processing of the baseband signals and for controlling operations of the RF circuitry1206. The baseband circuitry1210may handle various radio control functions.

The aforementioned circuitry and/or control logic of the baseband circuitry1210may include one or more single or multi-core processors. For example, the one or more processors may include a 3G baseband processor1204A, a 4G/LTE baseband processor1204B, a 5G/NR baseband processor1204C, or some other baseband processor(s)1204D for other existing generations, generations in development or to be developed in the future (e.g., sixth generation (6G), etc.). In other embodiments, some or all of the functionality of baseband processors1204A-D may be included in modules stored in the memory1204G and executed via a Central Processing Unit (CPU)1204E. In other embodiments, some or all of the functionality of baseband processors1204A-D may be provided as hardware accelerators (e.g., FPGAs, ASICs, etc.) loaded with the appropriate bit streams or logic blocks stored in respective memory cells. In various embodiments, the memory1204G may store program code of a real-time OS (RTOS), which when executed by the CPU1204E (or other baseband processor), is to cause the CPU1204E (or other baseband processor) to manage resources of the baseband circuitry1210, schedule tasks, etc. Examples of the RTOS may include Operating System Embedded (OSE)™ provided by Enea®, Nucleus RTOS™ provided by Mentor Graphics®, Versatile Real-Time Executive (VRTX) provided by Mentor Graphics®, ThreadX™ provided by Express Logic®, FreeRTOS, REX OS provided by Qualcomm®, OKL4 provided by Open Kernel (OK) Labs®, or any other suitable RTOS, such as those discussed herein. In addition, the baseband circuitry1210includes one or more audio digital signal processor(s) (DSP)1204F. The audio DSP(s)1204F include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.

In some embodiments, each of the processors1204A-1204E include respective memory interfaces to send/receive data to/from the memory1204G. The baseband circuitry1210may further include one or more interfaces to communicatively couple to other circuitries/devices, such as an interface to send/receive data to/from memory external to the baseband circuitry1210; an application circuitry interface to send/receive data to/from the application circuitry1005/1105ofFIGS. 10-XT); an RF circuitry interface to send/receive data to/from RF circuitry1206ofFIG. 12; a wireless hardware connectivity interface to send/receive data to/from one or more wireless hardware elements (e.g., Near Field Communication (NFC) components, Bluetooth®/Bluetooth® Low Energy components, Wi-Fi® components, and/or the like); and a power management interface to send/receive power or control signals to/from the PMIC1125.

In alternate embodiments (which may be combined with the above described embodiments), baseband circuitry1210comprises one or more digital baseband systems, which are coupled with one another via an interconnect subsystem and to a CPU subsystem, an audio subsystem, and an interface subsystem. The digital baseband subsystems may also be coupled to a digital baseband interface and a mixed-signal baseband subsystem via another interconnect subsystem. Each of the interconnect subsystems may include a bus system, point-to-point connections, network-on-chip (NOC) structures, and/or some other suitable bus or interconnect technology, such as those discussed herein. The audio subsystem may include DSP circuitry, buffer memory, program memory, speech processing accelerator circuitry, data converter circuitry such as analog-to-digital and digital-to-analog converter circuitry, analog circuitry including one or more of amplifiers and filters, and/or other like components. In an aspect of the present disclosure, baseband circuitry1210may include protocol processing circuitry with one or more instances of control circuitry (not shown) to provide control functions for the digital baseband circuitry and/or radio frequency circuitry (e.g., the radio front end modules1215).

Although not shown byFIG. 12, in some embodiments, the baseband circuitry1210includes individual processing device(s) to operate one or more wireless communication protocols (e.g., a “multi-protocol baseband processor” or “protocol processing circuitry”) and individual processing device(s) to implement PHY layer functions. In these embodiments, the PHY layer functions include the aforementioned radio control functions. In these embodiments, the protocol processing circuitry operates or implements various protocol layers/entities of one or more wireless communication protocols. In a first example, the protocol processing circuitry may operate LTE protocol entities and/or 5G/NR protocol entities when the baseband circuitry1210and/or RF circuitry1206are part of mmWave communication circuitry or some other suitable cellular communication circuitry. In the first example, the protocol processing circuitry would operate MAC, RLC, PDCP, SDAP, RRC, and NAS functions. In a second example, the protocol processing circuitry may operate one or more IEEE-based protocols when the baseband circuitry1210and/or RF circuitry1206are part of a Wi-Fi communication system. In the second example, the protocol processing circuitry would operate Wi-Fi MAC and logical link control (LLC) functions. The protocol processing circuitry may include one or more memory structures (e.g.,1204G) to store program code and data for operating the protocol functions, as well as one or more processing cores to execute the program code and perform various operations using the data. The baseband circuitry1210may also support radio communications for more than one wireless protocol.

The various hardware elements of the baseband circuitry1210discussed herein may be implemented, for example, as a solder-down substrate including one or more integrated circuits (ICs), a single packaged IC soldered to a main circuit board or a multi-chip module containing two or more ICs. In one example, the components of the baseband circuitry1210may be suitably combined in a single chip or chipset, or disposed on a same circuit board. In another example, some or all of the constituent components of the baseband circuitry1210and RF circuitry1206may be implemented together such as, for example, a system on a chip (SoC) or System-in-Package (SiP). In another example, some or all of the constituent components of the baseband circuitry1210may be implemented as a separate SoC that is communicatively coupled with and RF circuitry1206(or multiple instances of RF circuitry1206). In yet another example, some or all of the constituent components of the baseband circuitry1210and the application circuitry1005/1105may be implemented together as individual SoCs mounted to a same circuit board (e.g., a “multi-chip package”).

In some embodiments, the baseband circuitry1210may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry1210may support communication with an E-UTRAN or other WMAN, a WLAN, a WPAN. Embodiments in which the baseband circuitry1210is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

In some embodiments, the receive signal path of the RF circuitry1206may include mixer circuitry1206a, amplifier circuitry1206band filter circuitry1206c. In some embodiments, the transmit signal path of the RF circuitry1206may include filter circuitry1206cand mixer circuitry1206a. RF circuitry1206may also include synthesizer circuitry1206dfor synthesizing a frequency for use by the mixer circuitry1206aof the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry1206aof the receive signal path may be configured to down-convert RF signals received from the FEM circuitry1208based on the synthesized frequency provided by synthesizer circuitry1206d. The amplifier circuitry1206bmay be configured to amplify the down-converted signals and the filter circuitry1206cmay be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry1210for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry1206aof the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry1206aof the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry1206dto generate RF output signals for the FEM circuitry1208. The baseband signals may be provided by the baseband circuitry1210and may be filtered by filter circuitry1206c.

The synthesizer circuitry1206dmay be configured to synthesize an output frequency for use by the mixer circuitry1206aof the RF circuitry1206based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry1206dmay be a fractional N/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry1210or the application circuitry1005/1105depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the application circuitry1005/1105.

FEM circuitry1208may include a receive signal path, which may include circuitry configured to operate on RF signals received from antenna array1211, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry1206for further processing. FEM circuitry1208may also include a transmit signal path, which may include circuitry configured to amplify signals for transmission provided by the RF circuitry1206for transmission by one or more of antenna elements of antenna array1211. In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry1206, solely in the FEM circuitry1208, or in both the RF circuitry1206and the FEM circuitry1208.

In some embodiments, the FEM circuitry1208may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry1208may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry1208may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g, to the RF circuitry1206). The transmit signal path of the FEM circuitry1208may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry1206), and one or more filters to generate RF signals for subsequent transmission by one or more antenna elements of the antenna array1211.

The antenna array1211comprises one or more antenna elements, each of which is configured convert electrical signals into radio waves to travel through the air and to convert received radio waves into electrical signals. For example, digital baseband signals provided by the baseband circuitry1210is converted into analog RF signals (e.g., modulated waveform) that will be amplified and transmitted via the antenna elements of the antenna array1211including one or more antenna elements (not shown). The antenna elements may be omnidirectional, direction, or a combination thereof. The antenna elements may be formed in a multitude of arranges as are known and/or discussed herein. The antenna array1211may comprise microstrip antennas or printed antennas that are fabricated on the surface of one or more printed circuit boards. The antenna array1211may be formed in as a patch of metal foil (e.g., a patch antenna) in a variety of shapes, and may be coupled with the RF circuitry1206and/or FEM circuitry1208using metal transmission lines or the like.

Processors of the application circuitry1005/1105and processors of the baseband circuitry1210may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry1210, alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry1005/1105may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., TCP and UDP layers). As referred to herein, Layer 3 may comprise a RRC layer, described in further detail below. As referred to herein, Layer 2 may comprise a MAC layer, an RLC layer, and a PDCP layer, described in further detail below. As referred to herein, Layer 1 may comprise a PHY layer of a UE/RAN node, described in further detail below.

FIG. 13illustrates various protocol functions that may be implemented in a wireless communication device according to various embodiments. In particular,FIG. 13includes an arrangement1300showing interconnections between various protocol layers/entities. The following description ofFIG. 13is provided for various protocol layers/entities that operate in conjunction with the 5G/NR system standards and LTE system standards, but some or all of the aspects ofFIG. 13may be applicable to other wireless communication network systems as well.

The protocol layers of arrangement1300may include one or more of PHY1310, MAC1320, RLC1330, PDCP1340, SDAP1347, RRC1355, and NAS layer1357, in addition to other higher layer functions not illustrated. The protocol layers may include one or more service access points (e.g., items1359,1356,1350,1349,1345,1335,1325, and1315inFIG. 13) that may provide communication between two or more protocol layers.

The PHY1310may transmit and receive physical layer signals1305that may be received from or transmitted to one or more other communication devices. The physical layer signals1305may comprise one or more physical channels, such as those discussed herein. The PHY1310may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC1355. The PHY1310may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and MIMO antenna processing. In embodiments, an instance of PHY1310may process requests from and provide indications to an instance of MAC1320via one or more PHY-SAP1315. According to some embodiments, requests and indications communicated via PHY-SAP1315may comprise one or more transport channels.

Instance(s) of MAC1320may process requests from, and provide indications to, an instance of RLC1330via one or more MAC-SAPs1325. These requests and indications communicated via the MAC-SAP1325may comprise one or more logical channels. The MAC1320may perform mapping between the logical channels and transport channels, multiplexing of MAC SDUs from one or more logical channels onto TBs to be delivered to PHY1310via the transport channels, de-multiplexing MAC SDUs to one or more logical channels from TBs delivered from the PHY1310via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through HARQ, and logical channel prioritization.

Instance(s) of RLC1330may process requests from and provide indications to an instance of PDCP1340via one or more radio link control service access points (RLC-SAP)1335. These requests and indications communicated via RLC-SAP1335may comprise one or more RLC channels. The RLC1330may operate in a plurality of modes of operation, including; Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC1330may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC1330may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment.

Instance(s) of PDCP1340may process requests from and provide indications to instance(s) of RRC1355and/or instance(s) of SDAP1347via one or more packet data convergence protocol service access points (PDCP-SAP)1345. These requests and indications communicated via PDCP-SAP1345may comprise one or more radio bearers. The PDCP1340may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

Instance(s) of SDAP1347may process requests from and provide indications to one or more higher layer protocol entities via one or more SDAP-SAP1349. These requests and indications communicated via SDAP-SAP1349may comprise one or more QoS flows. The SDAP1347may map QoS flows to DRBs, and vice versa, and may also mark QFIs in DL and UL packets. A single SDAP entity1347may be configured for an individual PDU session. In the UL direction, the NG-RAN710may control the mapping of QoS Flows to DRB(s) in two different ways, reflective mapping or explicit mapping. For reflective mapping, the SDAP1347of a UE701may monitor the QFIs of the DL packets for each DRB, and may apply the same mapping for packets flowing in the UL direction. For a DRB, the SDAP1347of the UE701may map the UL packets belonging to the QoS flows(s) corresponding to the QoS flow ID(s) and PDU session observed in the DL packets for that DRB. To enable reflective mapping, the NG-RAN910may mark DL packets over the Uu interface with a QoS flow ID. The explicit mapping may involve the RRC1355configuring the SDAP1347with an explicit QoS flow to DRB mapping rule, which may be stored and followed by the SDAP1347. In embodiments, the SDAP1347may only be used in NR implementations and may not be used in LTE implementations.

The RRC1355may configure, via one or more management service access points (M-SAP), aspects of one or more protocol layers, which may include one or more instances of PHY1310, MAC1320, RLC1330, PDCP1340and SDAP1347. In embodiments, an instance of RRC1355may process requests from and provide indications to one or more NAS entities1357via one or more RRC-SAPs1356. The main services and functions of the RRC1355may include broadcast of system information (e.g., included in MIBs or SIBs related to the NAS), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE701and RAN710(e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter-RAT mobility, and measurement configuration for UE measurement reporting. The MIBs and SIBs may comprise one or more IEs, which may each comprise individual data fields or data structures.

The NAS1357may form the highest stratum of the control plane between the UE701and the AMF921. The NAS1357may support the mobility of the UEs701and the session management procedures to establish and maintain IP connectivity between the UE701and a P-GW in LTE systems.

According to various embodiments, one or more protocol entities of arrangement1300may be implemented in UEs701, RAN nodes711, AMF921in NR implementations or MME821in LTE implementations, UPF902in NR implementations or S-GW822and P-GW823in LTE implementations, or the like to be used for control plane or user plane communications protocol stack between the aforementioned devices. In such embodiments, one or more protocol entities that may be implemented in one or more of UE701, gNB711, AMF921, etc. may communicate with a respective peer protocol entity that may be implemented in or on another device using the services of respective lower layer protocol entities to perform such communication. In some embodiments, a gNB-CU of the gNB711may host the RRC1355, SDAP1347, and PDCP1340of the gNB that controls the operation of one or more gNB-DUs, and the gNB-DUs of the gNB711may each host the RLC1330, MAC1320, and PHY1310of the gNB711.

In a first example, a control plane protocol stack may comprise, in order from highest layer to lowest layer, NAS1357, RRC1355, PDCP1340, RLC1330, MAC1320, and PHY1310. In this example, upper layers1360may be built on top of the NAS1357, which includes an IP layer1361, an SCTP1362, and an application layer signaling protocol (AP)1363.

In NR implementations, the AP1363may be an NG application protocol layer (NGAP or NG-AP)1363for the NG interface713defined between the NG-RAN node711and the AMF921, or the AP1363may be an Xn application protocol layer (XnAP or Xn-AP)1363for the Xn interface712that is defined between two or more RAN nodes711.

The NG-AP1363may support the functions of the NG interface713and may comprise Elementary Procedures (EPs). An NG-AP EP may be a unit of interaction between the NG-RAN node711and the AMF921. The NG-AP1363services may comprise two groups: UE-associated services (e.g., services related to a UE701) and non-UE-associated services (e.g., services related to the whole NG interface instance between the NG-RAN node711and AMF921). These services may include functions including, but not limited to: a paging function for the sending of paging requests to NG-RAN nodes711involved in a particular paging area; a UE context management function for allowing the AMF921to establish, modify, and/or release a UE context in the AMF921and the NG-RAN node711; a mobility function for UEs701in ECM-CONNECTED mode for intra-system HOs to support mobility within NG-RAN and inter-system HOs to support mobility from/to EPS systems; a NAS Signaling Transport function for transporting or rerouting NAS messages between UE701and AMF921; a NAS node selection function for determining an association between the AMF921and the UE701; NG interface management function(s) for setting up the NG interface and monitoring for errors over the NG interface; a warning message transmission function for providing means to transfer warning messages via NG interface or cancel ongoing broadcast of warning messages; a Configuration Transfer function for requesting and transferring of RAN configuration information (e.g., SON information, performance measurement (PM) data, etc.) between two RAN nodes711via CN720; and/or other like functions.

The XnAP1363may support the functions of the Xn interface712and may comprise XnAP basic mobility procedures and XnAP global procedures. The XnAP basic mobility procedures may comprise procedures used to handle UE mobility within the NG RAN711(or E-UTRAN810), such as handover preparation and cancellation procedures, SN Status Transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, dual connectivity related procedures, and the like. The XnAP global procedures may comprise procedures that are not related to a specific UE701, such as Xn interface setup and reset procedures, NG-RAN update procedures, cell activation procedures, and the like.

In LTE implementations, the AP1363may be an S1 Application Protocol layer (S1-AP)1363for the S1 interface713defined between an E-UTRAN node711and an MME, or the AP1363may be an X2 application protocol layer (X2AP or X2-AP)1363for the X2 interface712that is defined between two or more E-UTRAN nodes711.

The S1 Application Protocol layer (S1-AP)1363may support the functions of the S1 interface, and similar to the NG-AP discussed previously, the S1-AP may comprise S1-AP EPs. An S1-AP EP may be a unit of interaction between the E-UTRAN node711and an MME821within an LTE CN720. The S1-AP1363services may comprise two groups: UE-associated services and non UE-associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer.

The X2AP1363may support the functions of the X2 interface712and may comprise X2AP basic mobility procedures and X2AP global procedures. The X2AP basic mobility procedures may comprise procedures used to handle UE mobility within the E-UTRAN720, such as handover preparation and cancellation procedures, SN Status Transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, dual connectivity related procedures, and the like. The X2AP global procedures may comprise procedures that are not related to a specific UE701, such as X2 interface setup and reset procedures, load indication procedures, error indication procedures, cell activation procedures, and the like.

The SCTP layer (alternatively referred to as the SCTP/IP layer)1362may provide guaranteed delivery of application layer messages (e.g., NGAP or XnAP messages in NR implementations, or S1-AP or X2AP messages in LTE implementations). The SCTP1362may ensure reliable delivery of signaling messages between the RAN node711and the AMF921/MME821based, in part, on the IP protocol, supported by the IP1361. The Internet Protocol layer (IP)1361may be used to perform packet addressing and routing functionality. In some implementations the IP layer1361may use point-to-point transmission to deliver and convey PDUs. In this regard, the RAN node711may comprise L2 and L1 layer communication links (e.g., wired or wireless) with the MME/AMF to exchange information.

In a second example, a user plane protocol stack may comprise, in order from highest layer to lowest layer, SDAP1347, PDCP1340, RLC1330, MAC1320, and PHY1310. The user plane protocol stack may be used for communication between the UE701, the RAN node711, and UPF902in NR implementations or an S-GW822and P-GW823in LTE implementations. In this example, upper layers1351may be built on top of the SDAP1347, and may include a user datagram protocol (UDP) and IP security layer (UDP/IP)1352, a General Packet Radio Service (GPRS) Tunneling Protocol for the user plane layer (GTP-U)1353, and a User Plane PDU layer (UP PDU)1363.

The transport network layer1354(also referred to as a “transport layer”) may be built on IP transport, and the GTP-U1353may be used on top of the UDP/IP layer1352(comprising a UDP layer and IP layer) to carry user plane PDUs (UP-PDUs). The IP layer (also referred to as the “Internet layer”) may be used to perform packet addressing and routing functionality. The IP layer may assign IP addresses to user data packets in any of IPv4, IPv6, or PPP formats, for example.

The GTP-U1353may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. The UDP/IP1352may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication on the selected data flows. The RAN node711and the S-GW822may utilize an S1-U interface to exchange user plane data via a protocol stack comprising an L1 layer (e.g., PHY1310), an L2 layer (e.g., MAC1320, RLC1330, PDCP1340, and/or SDAP1347), the UDP/IP layer1352, and the GTP-U1353. The S-GW822and the P-GW823may utilize an S5/S8a interface to exchange user plane data via a protocol stack comprising an L1 layer, an L2 layer, the UDP/IP layer1352, and the GTP-U1353. As discussed previously, NAS protocols may support the mobility of the UE701and the session management procedures to establish and maintain IP connectivity between the UE701and the P-GW823.

Moreover, although not shown byFIG. 13, an application layer may be present above the AP1363and/or the transport network layer1354. The application layer may be a layer in which a user of the UE701, RAN node711, or other network element interacts with software applications being executed, for example, by application circuitry1005or application circuitry1105, respectively. The application layer may also provide one or more interfaces for software applications to interact with communications systems of the UE701or RAN node711, such as the baseband circuitry1210. In some implementations the IP layer and/or the application layer may provide the same or similar functionality as layers 5-7, or portions thereof, of the Open Systems Interconnection (OSI) model (e.g., OSI Layer 7—the application layer, OSI Layer 6—the presentation layer, and OSI Layer 5—the session layer).

FIG. 14is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically,FIG. 14shows a diagrammatic representation of hardware resources1400including one or more processors (or processor cores)1410, one or more memory/storage devices1420, and one or more communication resources1430, each of which may be communicatively coupled via a bus1440. For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor1402may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources1400.

The processors1410may include, for example, a processor1412and a processor1414. The processor(s)1410may be, for example, a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a DSP such as a baseband processor, an ASIC, an FPGA, a radio-frequency integrated circuit (RFIC), another processor (including those discussed herein), or any suitable combination thereof.

The communication resources1430may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices1404or one or more databases1406via a network1408. For example, the communication resources1430may include wired communication components (e.g., for coupling via USB), cellular communication components, NFC components, Bluetooth® (or Bluetooth® Low Energy) components, Wi-Fi® components, and other communication components.

Instructions1450may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors1410to perform any one or more of the methodologies discussed herein. The instructions1450may reside, completely or partially, within at least one of the processors1410(e.g., within the processor's cache memory), the memory/storage devices1420, or any suitable combination thereof. Furthermore, any portion of the instructions1450may be transferred to the hardware resources1400from any combination of the peripheral devices1404or the databases1406. Accordingly, the memory of processors1410, the memory/storage devices1420, the peripheral devices1404, and the databases1406are examples of computer-readable and machine-readable media.