Quality of service (QOS) enhancement for a side-link relay

An approach is described for a user equipment (UE) comprising a transceiver configured to enable wireless communication with a second UE and a wireless device and a processor communicatively coupled to the transceiver. The processor is configured receive, from the second UE, an end-to-end (E2E) quality of service (QoS) requirement of an E2E connection between the second UE and the wireless device, wherein the E2E connection includes a first hop between the UE and the second UE and a second hop between the UE and the wireless device. The processor is further configured to obtain a first hop link condition and a second hop link condition; split the E2E QoS requirement into a first hop QoS requirement and a second hop QoS requirement based on the first hop link condition and the second hop link condition; and transmit, using the transceiver, the first hop QoS requirement to the second UE. The wireless device is a third UE or a base station.

This application is a U.S. National Phase of International Application No. PCT/CN2021/084512, filed Mar. 31, 2021, which is hereby incorporated by reference in its entirety.

BACKGROUND

Field

The described aspects generally relate to an enhancement on a quality of service (QoS) for side-link relay.

SUMMARY

Some aspects of this disclosure relate to apparatuses and methods for implementing a quality of service (QoS) enhancement for a side-link relay for 3rd Generation Partnership Project (3GPP) release 15 (Rel-15), release 16 (Rel-16), release 17 (Rel-17), and/or other 3GPP releases that support QoS splitting. For example, systems and methods are provided for implementing splitting an end-to-end QoS requirement based on link conditions.

Some aspects of this disclosure relate to a user equipment (UE) comprising a transceiver configured to enable wireless communication with a second UE and a wireless device and a processor communicatively coupled to the transceiver. The processor is configured receive, from the second UE, an end-to-end (E2E) quality of service (QoS) requirement of an E2E connection between the second UE and the wireless device, wherein the E2E connection includes a first hop between the UE and the second UE and a second hop between the UE and the wireless device. The processor is further configured to obtain a first hop link condition and a second hop link condition; split the E2E QoS requirement into a first hop QoS requirement and a second hop QoS requirement based on the first hop link condition and the second hop link condition; and transmit, using the transceiver, the first hop QoS requirement to the second UE. The wireless device is a third UE or a base station.

Some aspects of this disclosure relate to a method of operating operating a user equipment (UE) as a relay between a base station and a second UE. The method comprise obtaining a link condition of a second hop between UE and the second UE of an end-to-end (E2E) connection, wherein the first hop of the end-to-end (E2E) connection is between the base station and the UE. The method further comprises transmitting the link condition of the second hop to the base station and receiving, from the base station, a second hop quality of service (QoS) requirement.

Some aspects of this disclosure relate to a base station configured to serve a user equipment (UE) that is configured to provide a relay between a second UE and a wireless device, wherein an end-to-end (E2E) connection between the second UE and the wireless device includes a first hop between the second UE and the UE and a second hop between the UE and the wireless device, the base station comprising. The base station comprises a transceiver configured to enable wireless communication with the UE; and a processor, communicatively coupled to the transceiver. The processor is configured to generate a quality of service (QoS) enforcement configuration and transmit the QoS enforcement configuration to the UE. The QoS enforcement configuration includes an indication of enabling or disabling the UE to split an E2E QoS requirement associated with the E2E connection.

This Summary is provided merely for purposes of illustrating some aspects to provide an understanding of the subject matter described herein. Accordingly, the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter in this disclosure. Other features, aspects, and advantages of this disclosure will become apparent from the following Detailed Description, Figures, and Claims.

DETAILED DESCRIPTION

Some aspects of this disclosure include apparatuses and methods for implementing a quality of service (QoS) enhancement for a side-link relay for 3rd Generation Partnership Project (3GPP) release 15 (Rel-15), release 16 (Rel-16), release 17 (Rel-17), and/or other 3GPP releases. For example, systems and methods are provided for implementing designs for splitting an end-to-end QoS requirement based on link conditions.

According to some aspects, a user equipment (UE) that operates according to Release 15 (Rel-15), Release 16 (Rel-16), and/or Release 17 (Rel-17) and New Radio (NR) of 5thgeneration (5G) wireless technology for digital cellular networks as defined by 3rd Generation Partnership Project (3GPP) may support side-link connections with other UEs directly without connecting to a base station. For example, the UE connects with a second UE directly via a side-link connection. The UE also connects with a base station via a direct communication link, such as a Uu link. In some aspects, the second UE may be on a cell boundary of the base station or in a location not covered by the base station. The second UE may experience severe fading effects or interferences from other devices. In other words, the second UE is not able to connect with the base station directly. In some aspects, the UE relays packets between the second UE and the base station. For example, the second UE transmits a packet to the UE and the UE forwards the packet to the base station. The base station also transmits a packet to the second UE via the UE. In such a case, the second UE connects with the base station indirectly via the UE.

According to some aspects, the second UE connects with a third UE via the UE. For example, the UE connects with the third UE via a side-link connection. The second UE can transmit a packet to the UE, which forwards the packet to the third UE. In such a case, the second UE connects with the third UE indirectly via the UE.

According to some aspects, the second UE, the base station, and the third UE transmit packets with QoS requirements. For example, the QoS requirements include a priority, a packet delay budget (PDB), a packet error rate (PER), and others. A packet with a PDB of 10 ms is expected to be delivered to a destination within 10 ms. A packet may include a plurality of sub-packets. The packet is expected to have less than 10−2PER at the destination if the QoS requirements include a PER of 10−2. In some aspects, the QoS requirements also include a bit error rate (BER) and/or a symbol error rate (SER).

In some aspects, the base station assigns communication resources to a UE based on QoS requirements. For example, the UE transmits its QoS requirements to the base station, which assigns communication resources to the UE. The communication resources include bandwidth resources, scheduling resources, code resources, spatial resources, and others. The scheduling resources relate to a PDB requirement because the UE can schedule a packet transmission within the PDB with the scheduling resources. The bandwidth resources, the code resources, and the spatial resources relate to a PER requirement. However, for indirect connections, the communication resources may not be assigned properly. For example, the second UE determines an end-to-end (E2E) QoS requirement for the indirect connection between the second UE and the base station. The indirect connection includes the side-link connection between the second UE and the UE and the Uu link connection between the UE and the base station. The base station assigns communication resources to the UE, but not the second UE because the second UE locates outside a range of the base station. In addition, the second UE connects with the UE via the side-link connection directly, not via any base stations.

According to some aspects, the UE connects with a fourth UE. Similar to the second UE, the fourth UE connects with the base station via the UE indirectly. The UE multiplexes packets received from the second and the fourth UE and forwards them to the base station. In some aspects, the UE multiplexes the packets based on channel priorities. For example, the second UE transmits to the UE via a first channel and the fourth UE transmits to the UE via a second channel. The first channel has a higher priority than the second channel. In such a case, the UE prioritizes packets received via the first channel over packets received via the second channel. In some aspects, the first channel and the second channel have a same priority. In such a case, the UE prioritizes packets based on QoS statuses. For example, a first packet received via the first channel arrives at the UE with a 10 ms delay, while a second packet received via the second channel arrives at the UE on time. The UE prioritizes the first packet because the first packet has a more urgent latency.

FIG.1illustrates an example system100implementing designs of splitting an end-to-end QoS requirement based on link conditions, according to some aspects of the disclosure. Example system100is provided for the purpose of illustration only and does not limit the disclosed aspects. System100may include, but is not limited to, a base station102, such as a gNB, a UE104, a UE106, and a UE108. The UEs104,106, and108may be implemented as electronic devices configured to operate based on a wide variety of wireless communication techniques. These techniques may include, but are not limited to, techniques based on 3rd Generation Partnership Project (3GPP) standards. For example, the UEs104,106, and108may include electronic devices configured to operate using one or more 3GPP releases, such as Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), or other 3GPP releases. The UEs104,106, and108may include, but is not limited to, wireless communication devices, smartphones, laptops, desktops, tablets, personal assistants, monitors, televisions, wearable devices, Internet of Things (IoT) devices, vehicle communication devices, and the like. The base station102may include one or more nodes configured to operate based on a wide variety of wireless communication techniques such as, but not limited to, techniques based on 3GPP standards. For example, the base station102may include nodes configured to operate using Rel-15, Rel-16, Rel-17, or other 3GPP releases. In some aspects, the UE104is in a cell coverage of the base station102and connects with the base station102via a communication link110. The communication link110may be a Uu link. The UE106and the UE108locate outside the cell coverage of the base station102. For example, the UE106and the UE108may locate on a cell boundary of the base station102or in a location far away from the base station102. The UE106and the UE108may experience severe fading effects or interferences from other devices. Therefore, the UE106and the UE108cannot connect with the base station102directly.

According to some aspects, the UE106and the UE108connect with the UE104directly via a communication link114and a communication link112, respectively. The communication links114and112may be side-link connections. In some aspects, the UE106and the UE108can connect with the base station102indirectly via the UE104. For example, the UE106transmits a packet to the UE104, which forwards the packet to the base station102. The base station102transmits a second packet to the UE104, which forwards the second packet to the UE106. In other words, the UE106connects with the base station102via a two-hop connection, wherein the communication link114is a first hop and the communication link110is a second hop.

According to some aspects, the two-hop connection has one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a priority, a packet delay budget (PDB), a packet error rate (PER), and others. A packet with a PDB of 10 ms is expected to be delivered to a destination within 10 ms. A packet may include a plurality of sub-packets. The packet is expected to have less than 10−2PER at the destination if the one or more E2E QoS requirements include a PER of 10−2. In some aspects, the one or more E2E QoS requirements also include a bit error rate (BER) and/or a symbol error rate (SER). Because the two-hop connection includes the first and the second hops, transmissions of the first and the second hop needs to satisfy the one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a PDB of 100 ms. Therefore, a total transmission time of the first and the second hops needs to be less than 100 ms.

According to some aspects, the UE104splits each of the one or more E2E QoS requirements into two parts: a first hop QoS requirement corresponding to the communication link114and a second hop QoS requirement corresponding to the communication link110. In some aspects, the base station102splits the one or more E2E QoS requirements and transmits the firs hop and the second hop QoS requirements to the UE104and the UE106.

In some aspects, the UE104splits the one or more E2E QoS requirements with a constant ratio. For example, the UE104splits the E2E QoS requirement to the first hop QoS requirement and the second hop QoS requirement equally in embodiments. Alternatively, the UE104splits the one or more E2E QoS requirements to the first hop and the second hop QoS requirements unequally, but the QoS requirement is still represented as a ratio.

In some aspects, side-link connections, such as the communication link114, are subject to channel resource sharing and congestions. It is more challenging for the side-link connections to fulfill a QoS requirement than for Uu links, such as the communication link110. This is because the side-links and the Uu links have different channel environments, communication resources, power constraints, congestion scenarios, and others. Therefore, the UE104or the base station102can splits the one or more E2E QoS requirements based on link conditions of the side-links and the Uu links. For example, the one or more E2E QoS requirements include a PDB of 100 ms. The UE104can assign 70 ms to the communication link114and assign 30 ms to the communication link110based on link conditions of the communication link114and the communication link110. The link conditions include a channel busy ratio (CBR), signal strengths such as a reference signal received power (RSRP) and a reference signal received quality (RSRQ), interference conditions, available communication resources, fading conditions, and others.

According to some aspects, the link conditions of the communication link114and the communication link110are subject to change over time. For example, the interference conditions change according to a number of nearby devices that perform transmission. The fading conditions change according to positions of the UE106and the UE104. The CBR changes according to a number of packets that require transmission. Therefore, the communication link114and the communication link110may not satisfy the first hop and the second hop QoS requirements previously assigned. In such as case, the UE104adjusts the QoS requirements based on updated link conditions.

In some aspects, the UE104can adjust the first hop and the second hop QoS requirements for individual packets. For example, after the UE104receives a packet from the UE106, the UE104determines a QoS status of the communication link114. The QoS status indicates that the communication link114outperforms or underperforms the first hop QoS requirement. For example, referring to the previous example, the first hop QoS requirement is 70 ms, which means that the UE104needs to receive the packet within 70 ms after the UE106generates the packet. However, due to a change of the link condition of the communication link114, the UE104receives the packet at 80 ms. Therefore, the communication link114creates a 10 ms excess delay. If the second hop QoS requirement remains the same, the packet will arrive at the base station102with a 10 ms excess delay.

In some aspects, to compensate, the UE104adjusts the second hop QoS requirement based on the delay of the communication link114. For example, the UE104adjusts the second hop QoS requirement from 30 ms to 20 ms to mitigate the 10 ms excess. In such a case, if the communication link110fulfills the adjusted second hop QoS requirement, an E2E packet delivery time is 100 ms, which still satisfies the one or more E2E QoS requirements of 100 ms.

In some aspects, the UE104adjusts the second hop QoS requirement based on instructions of the base station102. For example, the UE104transmits the QoS status of the communication link114to the base station102. The base station102determines the adjusted second hop QoS requirement of the communication link110and transmits the adjusted second hop QoS requirement to the UE104.

In some aspects, the UE104adjusts communication resources of the communication link110to allow the communication link110to achieve the adjusted second hop QoS requirement. In some aspects, the adjusted second hop QoS requirement can be tighter than the second hop QoS requirement assigned previously. For example, referring to the example above, the UE104adjusts the second hop QoS requirement from 30 ms to 20 ms. The communication link110is required to deliver the packet in a shorter time. In such a case, the UE104schedules the packet for transmission in time frames that are sooner. In some aspects, the adjusted second hop QoS requirement can be looser than the second hop QoS requirement assigned previously. For example, the UE104adjusts the second hop QoS requirement from 30 ms to 40 ms. This is possible when the communication link114outperforms the first hop QoS requirement. In such a case, the UE104schedules the packet for transmission in time frames that are later. The UE104releases time frames that were originally assigned to the packet and can use the time frames to transmit other more packets.

According to some aspects, the UE106cannot connect with the UE108directly. For example, the UE106and the UE108are far away from each other. Because the UE106and the UE108both connect with the UE104, a two-hop connection via the UE104between the UE106and UE108is possible. For example, the UE106transmits a packet to the UE104, which forwards the packet to the UE108. Similar to the two-hop connection between the UE106and the base station102discussed above, the two-hop connection between the UE106and the UE108also has one or more E2E QoS requirements. The UE104can split the one or more E2E QoS requirements based on conditions of the communication link114and the communication link112in a similar way as discussed above.

FIG.2illustrates a block diagram of an example system200of an electronic device implementing a QoS enhancement for a side-link relay, according to some aspects of the disclosure. The system200may be any of the electronic devices (e.g., the base station102and the UEs104,106, and108) of the system100. The system200includes a processor210, one or more transceivers220, a communication infrastructure240, a memory250, an operating system252, an application254, and one or more antennas260. Illustrated systems are provided as exemplary parts of system200, and system200may include other circuit(s) and subsystem(s). Also, although the systems of system200are illustrated as separate components, the aspects of this disclosure may include any combination of these, e.g., less, or more components.

The memory250may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer software) and/or data. The memory250may include other storage devices or memory. According to some examples, the operating system252may be stored in the memory250. The operating system252may manage transfer of data from the memory250and/or the one or more applications254to the processor210and/or the one or more transceivers220. In some examples, the operating system252maintains one or more network protocol stacks (e.g., Internet protocol stack, cellular protocol stack, and the like) that may include a number of logical layers. At corresponding layers of the protocol stack, the operating system252includes control mechanisms and data structures to perform the functions associated with that layer.

According to some examples, the application254may be stored in the memory250. The application254may include applications (e.g., user applications) used by wireless system200and/or a user of wireless system200. The applications in the application254may include applications such as, but not limited to. Siri™, FaceTime™, radio streaming, video streaming, remote control, and/or other user applications.

The system200may also include the communication infrastructure240. The communication infrastructure240provides communication between, for example, the processor210, the one or more transceivers220, and the memory250. In some implementations, the communication infrastructure240may be a bus.

The processor210, alone, or together with instructions stored in the memory250performs operations enabling system200of the system100to implement mechanisms for the QoS enhancement for the side-link relay, as described herein. Alternatively, or additionally, the processor210can be “hard coded” to implement mechanisms for the QoS enhancement for the side-link relay, as described herein

The one or more transceivers220transmit and receive communications signals support mechanisms for the QoS enhancement for the side-link relay. Additionally, the one or more transceivers220transmit and receive communications signals that support mechanisms for measuring communication link(s), generating and transmitting system information, and receiving the system information. According to some aspects, the one or more transceivers220may be coupled to antenna260to wirelessly transmit and receive the communication signals. Antenna260may include one or more antennas that may be the same or different types. The one or more transceivers220allow system200to communicate with other devices that may be wired and/or wireless. In some examples, the one or more transceivers220may include processors, controllers, radios, sockets, plugs, buffers, and like circuits/devices used for connecting to and communication on networks. According to some examples, the one or more transceivers220include one or more circuits to connect to and communicate on wired and/or wireless networks.

According to some aspects of this disclosure, the one or more transceivers220may include a cellular subsystem, a WLAN subsystem, and/or a Bluetooth™ subsystem, each including its own radio transceiver and protocol(s) as will be understood by those skilled in the arts based on the discussion provided herein. In some implementations, the one or more transceivers220may include more or fewer systems for communicating with other devices.

In some examples, the one or more the transceivers220may include one or more circuits (including a WLAN transceiver) to enable connection(s) and communication over WLAN networks such as, but not limited to, networks based on standards described in IEEE 802.11.

Additionally, or alternatively, the one or more the transceivers220may include one or more circuits (including a Bluetooth™ transceiver) to enable connection(s) and communication based on, for example, Bluetooth™ protocol, the Bluetooth™ Low Energy protocol, or the Bluetooth™ Low Energy Long Range protocol. For example, the transceiver220may include a Bluetooth™ transceiver.

Additionally, the one or more the transceivers220may include one or more circuits (including a cellular transceiver) for connecting to and communicating on cellular networks. The cellular networks may include, but are not limited to, 3G/4G/5G networks such as Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE), and the like. For example, the one or more transceivers220may be configured to operate according to one or more of Rel-15, Rel-16, Rel-17, or other releases of 3GPP standard.

As discussed in more detail below with respect toFIGS.3-8, processor210may implement different mechanisms for the QoS enhancement for the side-link relay as discussed with respect to the system100ofFIG.1.

FIG.3Aillustrates an example system of a side-link relay system connecting a UE and a base station. Example system300is provided for the purpose of illustration only and does not limit the disclosed aspects. System300may include, but is not limited to, the UE106, the UE104, and the base station102. Similar to the discussion above, the UE106connects with the base station102via a two-hop connection302. The two-hop connection302includes a first hop304and a second hop306.

According to some aspects, the two-hop connection302has one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a priority, a PDB, a PER, and others. The first hop304and the second hop306also have one or more first hop QoS requirements and one or more second hop QoS requirements, respectively. A combination of the one or more first hop and second hop QoS requirements need to satisfy the one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a PDB of X1ms. The one or more first hop QoS requirements include a first PDB of X1ms and the one or more second hop QoS requirements include a second PDB of X2ms. To satisfy the PDB. X1and X2need to satisfy X1+X2≤X. The one or more E2E QoS requirements may also include a PER of E. The one or more first hop QoS requirements include a first PER of E1and the one or more second hop QoS requirements include a second PER of E2. To satisfy the PER, E1and E2need to satisfy (1−E1)×(1−E2)≤(1−E). The one or more E2E QoS requirements may also include a priority of Y. The one or more first hop QoS requirements include a first priority of Y1and the one or more second hop QoS requirements include a second priority of Y2. To satisfy the priority, Y2needs to satisfy Y2≤Y. Here, a lower priority value corresponds to a higher priority.

According to some aspects, the UE104determines the one or more first hop and second hop QoS requirements based on link conditions of the first hop304and the second hop306. For example, the link conditions include CBRs of the first hop304and the second hop306. A higher CBR value corresponds to a more severe congestion condition in a communication link. If a CBR of the first hop304is larger than a CBR of the second hop306, the UE104determines that the first PDB is larger than the second PDB, i.e., X1>X2. This is because the first hop304is expected to experience a more severe congestion than the second hop306. Therefore, a looser QoS requirement of the PDB is assigned to the first hop304. In some aspects, the link conditions include signal strengths, such as an RSRP and an RSRQ, of the first hop304and the second hop306. A higher signal strength value may correspond to a higher signal-to-noise ratio (SNR) at a receiver side of a communication link. In addition, a higher SNR may correspond to a lower PER. If a signal strength of the first hop304is smaller than a signal strength of the second hop306, the UE104determines that the first PER is larger than the second PER, i.e., E1>E2. This is because the PER of the first hop304is expected to be higher than the PER of the second hop306. Therefore, a looser QoS requirement of PER is assigned to the first hop304.

In some aspects, the UE104determines the one or more first hop and second hop QoS requirements proportionally to the link conditions. For example, the CBR of the first hop304is C1and the CBR of the second hop306is C2. The UE104determines that the

In some aspects, the UE104determines the one or more first hop and second hop QoS requirements based on a splitting table. The splitting table includes a plurality of dimensions. Each dimension corresponds to one kind of first hop and second hop QoS requirements. For example, Table 1 shown below corresponds to the PDB QoS requirements. If the first hop304has a CBR value of C1−3 and the second hop306has a CBR value of C2−4, the UE104determines that the first PDB of the first hop304is X1−34 and the second PDB of the second hop306is X2−34. In other words, the UE104determines the one or more first hop and second hop QoS requirements by accessing the splitting table. In some aspects, a CBR value may not be listed in the splitting table. For example, the first hop304has a CRB value C1−n, wherein C1−1<C1−n<C1−2. The second hop306has a CRB value C2−1. The UE104determines that the first PDB to be a value between X1−11 and X1−21 and the second PDB to be a value between X2−11 and X2−21.

In some aspects, the splitting table also includes the one or more first hop and second hop QoS requirements, such as the PER and the priority. For example, the UE104determines the PER of the first hop304and the PER of the second hop306based on the splitting table similarly as discussed above.

In some aspects, the UE104receives the splitting table from the base station102. The base station102generates the splitting table. In other aspects, the base station102receives the splitting table from a core network. For example, the base station102receives the splitting table from a policy control function (PFC) of the core network.

In some aspects, the UE104determines the one or more first hop and second hop QoS requirements based on instructions received from the base station102. For example, the UE104transmits the link conditions of the first hop304and the second hop306to the base station102. The base station102determines the one or more first hop and second hop QoS requirements and transmits them to the UE104.

In some aspects, the UE104measures the link conditions of the first hop304and the second hop306. For example, the UE104measures the signal strength of the first hop304by measuring received signals from the UE106. The UE104also measures the CBR of the second hop306by measuring a number of nearby devices and their transmission rates. In some aspects, the UE104receives the link conditions from other devices such as the UE106and the base station102. For example, the UE104receives the CBR of the first hop304from the UE106and receives the signal strength of the second hop306from the base station102. In some aspects, the UE104transmits the link conditions that are unknown to the base station102to the base station102for determining the one or more first hop and second hop QoS requirements. For example, the UE104transmits the CBR of the second hop306to the base station102.

In some aspects, the UE104updates the one or more first hop and second hop QoS requirements based on updated link conditions of the first hop304and the second hop306. For example, the CBR of the first hop304and the CBR of the second hop306are updated periodically or on-demand when the CBRs change. In some aspects, the first hop304is less capable or stable than the second hop306. For example, the first hop304is subjected to a more strict power constraint than the second hop306. The first hop304may suffer from a more severe fading effect than the second hop306because both the UE106and the UE104of the first hop304are mobile. Therefore, the UE104updates the one or more first hop and second hop QoS requirements based solely on the link conditions of the first hop304. In other words, the UE104presumes that the link conditions of the second hop306do not change. In some aspects, because the second hop306is more stable as explained above, the UE104determines that the one or more first hop QoS requirements are looser than the one or more second hop QoS requirements even if the link conditions of the first hop304and the second hop306are the same. For example, as shown in Table 1, the UE104determines that X1−33 is greater than X2−33, even if C1−3=C2−3.

FIG.3Billustrates an example system of a side-link relay system connecting multiple UEs. Example system300is provided for the purpose of illustration only and does not limit the disclosed aspects. System300may include, but is not limited to, the UE104, the UE106, and the UE108. Similar to the discussion above, the UE106connects with the UE108via a two-hop connection308. The two-hop connection308includes a first hop310and a second hop312.

According to some aspects, similar as discussed above, the two-hop connection308has one or more E2E QoS requirements. For example, the one or more E2E QoS requirements include a priority, a PDB, a PER, and others. The first hop310and the second hop312also have one or more first hop QoS requirements and one or more second hop QoS requirements, respectively. A combination of the one or more first hop and second hop QoS requirements need to satisfy the one or more E2E QoS requirements. Regarding the PDB and the PER. The one or more first hop and second hop QoS requirements satisfy the one or more E2E QoS requirements in a same way as described inFIG.3Adiscussed above. Regarding the priority, the one or more E2E QoS requirements may include a priority of Y. The one or more first hop QoS requirements include a first priority of Y1and the one or more second hop QoS requirements include a second priority of Y2. To satisfy the priority, Y1and Y2need to satisfy Y2≤Y and Y1≤Y. Here, a lower priority value corresponds to a higher priority.

In some aspects, the UE104determines the one or more first hop and second hop QoS requirements similarly as discussed inFIG.3Aabove. For example, the UE104determines the one or more first hop and second hop QoS requirements based on relative values of link conditions of the first hop310and the second hop312. The UE104determines the one or more first hop and second hop QoS requirements based on a ratio between the link conditions of the first hop310and the second hop312. The UE104determines the one or more first hop and second hop QoS requirements based on a second splitting table. The UE104receives the second splitting table from the base station102. In some aspects, the second splitting table has a similar structure to the splitting table discussed inFIG.3A. For example, for each kind of QoS requirement, such as the PDB, the UE104looks up the second splitting table based on the link conditions to determine a first PDB of the first link310and a second PDB of the second link312. On the other hand, unlike the two-hop connection302ofFIG.3A, which includes the second hop306that is a Uu link connection, the two-hop connection308ofFIG.3Bincludes the first hop310and the second hop312that are both side-link connections. Therefore, in the second splitting table, if the channel conditions of the first hop310and the second hop312are the same, the one or more first hop and second hop QoS requirements are the same.

In some aspects, the UE104determines the one or more first hop and second hop QoS requirements based on instructions received from the base station102. For example, the UE104transmits the link conditions of the first hop310and the second hop312to the base station102. The base station102determines the one or more first hop and second hop QoS requirements and transmits them to the UE104. In some aspects, because the base station102is not a part of the two-hop connection308, the UE104gathers all the link conditions of the first hop310and the second hop312and transmits them to the base station102.

FIGS.4A-4Billustrate an example method400for a system implementing a QoS enhancement for a side-link relay. As a convenience and not a limitation,FIG.4may be described with regard to elements ofFIGS.1,2,3, and8. Method400may represent the operation of electronic devices (for example, the base stations102, the UE104, and the UE106ofFIG.1) implementing the QoS enhancement for the side-link relay. For the sake of demonstration, the UE104is referred to as a relay UE104and the UE106is referred to as a remote UE106. The remote UE106connects with the base station102by a two-hop connection via the relay UE104. The two-hop connection includes a first hop between the remote UE106and the relay UE104and a second hop between the relay UE104and the base station102. Method400may also be performed by system200ofFIG.2and/or computer system800ofFIG.8. But method400is not limited to the specific aspects depicted in those figures and other systems may be used to perform the method, as will be understood by those skilled in the art. It is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown inFIG.4.

At402, the relay UE104transmits an enhanced relay QoS capability message to the base station102. The enhanced relay QoS capability message indicates that the relay UE104is capable of splitting one or more E2E QoS requirements for a multi-hop connection, such as the two-hop connection between the remote UE106and the base station102, as discussed above. In addition, the enhanced relay QoS capability message also indicates that the relay UE104is capable of adjusting QoS requirements for a hop connection, such as the second hop, based on a received packet.

At404, the relay UE104transmits the enhanced relay QoS capability message to the remote UE106. The enhanced relay QoS capability message may be identical to the one that is sent to the base station102in402. In response to receiving the enhanced relay QoS capability, the remote UE106enables an outlier mode by transmitting packets when the remote UE106expects that the packets do not meet QoS requirements of the first hop. For example, the remote UE106transmits a packet even when the remote UE106expects that the packet will arrive at the relay UE104with an excess delay, such as a 10 ms delay. This is because the remote UE106expects that the second hop will make up for the 10 ms delay based on the enhanced relay QoS capability message.

At406, the base station102obtains an E2E QoS requirement corresponding to the two-hop connection between the remote UE106and the base station102. The E2E QoS requirement includes a priority, a PDB, a PER, or others. In an uplink scenario, the remote UE106determines the E2E QoS requirement. The remote UE106can determine the E2E QoS requirement based on instructions received from an application of the remote UE106, such as the application254of theFIG.2. The remote UE106can also receive the E2E QoS requirement from a user of the remote UE106. Furthermore, the remote UE106transmits the E2E QoS requirement to the base station102via the relay UE104. In a downlink scenario, the base station102determines the E2E QoS requirement. The base station102may also transmits the E2E QoS requirement to the relay UE104.

At408, the relay UE104transmits a first hop link condition measurement to the base station102. The first hop link condition measurement includes a CBR of the first hop, a signal strength of the first hop, i.e., a side-link reference signal received power (SL-RSRP), an interference level of the first hop, and others. The relay UE104measures a first hop link condition at the relay UE104. For example, the relay UE104measures a signal strength of the first hop based on signals received at the relay UE104. The relay UE104also receives the first hop link condition from the remote UE106. For example, the remote UE106measures a CBR of the first hop and transmits the CBR to the relay UE104.

At410, the base station102measures a second hop link condition. For example, the base station102measures a signal strength of the second hop based on signals received at the base station102. In some aspects, the base station102receives the second hop link condition. For example, the base station102receives a CBR of the second hop from the relay UE104. In some aspects, the second hop is a Uu link. The second hop link condition is measured based on radio resource measurement (RRM).

At412, the base station102assigns QoS requirements for the first hop and the second hop based on the link conditions of the first hop and the second hop. The base station102can assign the QoS requirements based on a splitting table as discussed above inFIG.3A. In some aspects, the base station102transmits the splitting table to the relav UE104and the relay UE104assigns the QoS requirements based on the splitting table.

At414, the base station102transmits the QoS requirement of the second hop to the relay UE104. In some aspects, the base station102also assigns corresponding communication resources to the second hop and notifies the relay UE104. The relay UE104adjusts the second hop connection based on the QoS requirement and the communication resources.

At416, the base station102transmits the QoS requirement of the first hop to the remote UE106via the relay UE104. The remote UE106and the relay UE104adjust the first hop connection based on the QoS requirement. In some aspects, the remote UE106and the relay UE104adjust communication resources of the first hop based on the QoS requirement.

At418, the relay UE104receives a packet. The packet has information corresponding to the E2E QoS requirement. For example, the information includes a packet generating time and an expected arrival time at a destination. The difference between the packet generating time and the expected arrival time at the destination is less than the PDB of the E2E QoS requirement. In other words, the packet needs to be delivered to the destination within the PDB of the E2E QoS requirement. In some aspects, the relay UE104receives the packet from the remote UE106. In such a case, the packet is an uplink packet and the destination is the base station102. In other aspects, the relay UE104receives the packet from the base station102. In such a case, the packet is a downlink packet and the destination is the remote UE106.

At420, the relay UE104determines a hop QoS status. In the uplink scenario, the hop QoS status is a first hop QoS status. The first hop QoS status indicates whether or not the first hop fulfills the QoS requirement of the first hop. For example, the QoS requirement of the first hop includes a PDB of 70 ms. The relay UE104determines a current time of receiving the packet and subtracts the packet generating time included in the packet to obtain a first hop transmission time of 80 ms. In such a case, the first hop QoS status indicates an excess delay of 10 ms. In the downlink scenario, the hop QoS status is a second hop QoS status corresponding the second hop. The relay UE104determines the second hop QoS status similarly as the first hop QoS status.

At422, the relay UE104determines an updated QoS requirement. For example, in the uplink scenario, the QoS requirement of the second hop includes a PDB of 30 ms. Based on the delay of the first hop QoS status, the relay UE104updates the QoS requirement of the second hop to be 20 ms. In this way, the second hop makes up the excess delay of the first hop and the packet is expected to arrive at the base station102within an expected delay. On the other hand, in the downlink scenario, the relay UE104updates the QoS requirement of the first hop similarly as discussed above.

At424, the relay UE104determines communication resources based on the updated QoS requirement. For example, in the uplink scenario, the relay UE104updates the QoS requirement of the second hop from 30 ms to 20 ms to mitigate the excess 10 ms delay per the continuing example. The relay UE104determines that time frames closer to the current time are needed for transmitting the packet in the second hop. In the downlink scenario, the relay UE104may also determine communication resources of the first hop.

At426, the relay UE104transmits a communication resource request to the base station102. The communication resource request indicates the communication resources. In some aspects, the relay UE104connects with the base station via a first channel and a second channel. The first channel corresponds to a first logical channel group and the second channel corresponds to a second logical channel group. The first logical channel group has a higher priority than the second logical channel group. For example, if the communication resource request corresponds to the first logical channel group, the base station102is more likely to grant the communication resources. Otherwise, the base station102may ignore the communication resource request. The relay UE104indicates in the communication resource request whether the communication resources correspond to the first logical channel group or the second logical channel group. The relay UE104can improve a chance of receiving the communication resources by indicating the first logical channel group in the communication resource request regardless. For example, the communication resources correspond to the second logical channel group. Nevertheless, the relay UE104indicates in the communication resource request that the communication resources correspond to the first logical channel group. In some aspects, the relay UE104assigns the communication resources to the second hop without permission from the base station102.

At428, the base station102assigns the communication resources to the second hop or the first hop based on the communication resource request. In some aspects, the base station102assigns based on the logical channel group corresponding to the communication resources.

At430, the base station102transmits a confirmation of the communication resources to the relay UE104. The confirmation indicates the communication resources of the communication resource request are granted. In some aspects, the confirmation indicates communication resources that are different from the communication resources of the communication resource request. For example, the base station102determines that the communication resources indicated by the communication resource request are not available or not suitable.

At432, the relay UE104forwards the packet using the communication resources that are granted by the base station. For example, in the uplink scenario, the relay UE104adjusts the second hop connection based on the communication resources and the updated QoS requirement of the second hop and transmits the packet using the adjusted second hop connection. In the downlink scenario, the relay UE104forwards the packet to the remote UE106using the communication resources assigned.

FIGS.5A-5Billustrate an example method500for a system implementing a QoS enhancement for a side-link relay. As a convenience and not a limitation,FIG.5may be described with regard to elements ofFIGS.1,2,3, and8. Method500may represent the operation of electronic devices (for example, the base stations102, the UE104, the UE106, and the UE108ofFIG.1) implementing the QoS enhancement for the side-link relay. For the sake of demonstration, the UE104is referred to as a relay UE104; the UE106is referred to as a remote UE106; and the UE108is referred to as a target UE108. The remote UE106connects with the target UE108by a two-hop connection via the relay UE104. The two-hop connection includes a first hop between the remote UE106and the relay UE104and a second hop between the relay UE104and the target UE108. Method500may also be performed by system200ofFIG.2and/or computer system800ofFIG.8. But method500is not limited to the specific aspects depicted in those figures and other systems may be used to perform the method, as will be understood by those skilled in the art. It is to be appreciated that not all operations may be needed, and the operations may not be performed in the same order as shown inFIG.5.

At502, the relay UE104transmits an enhanced relay QoS capability message to the base station102. The enhanced relay QoS capability message indicates that the relay UE104is capable of splitting one or more E2E QoS requirements for a multi-hop connection, such as the two-hop connection between the remote UE106and the target UE108, as discussed above. In addition, the enhanced relay QoS capability, message also indicates that the relay UE104is capable of adjusting QoS requirements for a hop connection, such as the second hop, based on a received packet.

At504, the relay UE104transmits the enhanced relay QoS capability message to the remote UE106. The enhanced relay QoS capability message may be identical to the one that is sent to the base station102in402. In response to receiving the enhanced relay QoS capability, the remote UE106enables an outlier mode by transmitting packets even when the remote UE106expects that the packets do not meet QoS requirements of the first hop. For example, the remote UE106transmits a packet even when the remote UE106expects that the packet will arrive at the relay UE104with an excess delay, e.g., 10 ms delay. This is because the remote UE106expects that the second hop will make up for the 10 ms delay based on the enhanced relay QoS capability message.

At506, the base station102transmits a QoS enforcement configuration to the relay UE104. In some aspects, the QoS enforcement configuration enables or disables enhanced relay QoS functions of the relay UE104. For example, the QoS enforcement configuration instructs the relay UE104whether to split one or more E2E QoS requirements of the two-hop connection. In addition, the QoS enforcement configuration instructs the relay UE104whether to adjust QoS requirements of the second hop based on the received packet. In some aspects, the QoS enforcement configuration further includes a splitting table as discussed inFIG.3A. The relay UE104can split the one or more E2E QoS requirements based on the splitting table. In some aspects, if a radio resource control (RRC) connection between the relay UE104and the base station102is idle or inactive, the base station102includes the QoS enforcement configuration in a system information block (SIB) and transmits the SIB to the relay UE104. If the RRC connection is active, the base station102transmits the QoS enforcement configuration through a dedicated RRC connection. If the relay UE104is out of coverage of the base station102, the relay UE104uses a QoS enforcement configuration previously received or pre-configured.

At508, the remote UE106transmits an E2E QoS requirement to the relay UE104. The E2E QoS requirement includes a priority, a PDB, a PER, or others. The remote UE106receives the E2E QoS requirement from an application of the remote UE106, such as the application254of theFIG.2. The remote UE106can also receive the E2E QoS requirement from a user of the remote UE106.

At510, the relay UE104measures a first hop link condition at the relay UE104. The first hop link condition includes a CBR of the first hop, a signal strength of the first hop, an interference level of the first hop, and others. For example, the relay UE104measures a signal strength of the first hop based on signals received at the relay UE104. The relay UE104also receives the first hop link condition from the remote UE106. For example, the remote UE106measures a CBR of the first hop and transmits the CBR to the relay UE104.

At512, the target UE108measures a second hop link condition. For example, the target UE108measures a signal strength of the second hop based on signals received at the target UE108.

At514, the target UE108transmits the second hop link condition to the relay UE104. In some aspects, the target UE108only transmits the second link condition that is unknown to the relay UE104. For example, the target UE108does not transmit a CBR of the second hop because the relay UE104can measure the CBR of the second hop.

At516, the relay UE104determines the QoS requirements to the first hop and the second hop based on the link conditions of the first hop and the second hop. The relay UE104can assign the QoS requirements based on the splitting table received from the base station102. In some aspects, the relay UE104determines the QoS requirements based on instructions from the base station102. For example, the relay UE104transmits the link conditions of the first and the second hops to the base station102. The base station102determines the QoS requirements based on the link conditions and transmits the QoS requirements to the relay UE104.

At518, the relay UE104transmits the QoS requirement of the first hop to the remote UE106. The remote UE106and the relay UE104adjust the first hop connection based on the QoS requirement of the first hop. In some aspects, the remote UE106and the relay UE104adjust communication resources of the first hop based on the QoS requirement.

At520, the remote UE106transmits a packet to the relay UE104. The packet has information corresponding to the E2E QoS requirement. For example, the information includes a packet generating time and an expected arrival time at the base station102. The difference between the packet generating time and the expected arrival time at the base station102is less than the PDB of the E2E QoS requirement. In other words, the packet needs to be delivered to the base station102within the PDB of the E2E QoS requirement.

At522, the relay UE104determines a first hop QoS status. In some aspects, the first hop QoS status indicates whether or not the first hop fulfills the QoS requirement of the first hop. For example, the QoS requirement of the first hop includes a PDB of 70 ms. The relay UE104determines a current time of receiving the packet and subtracts the packet generating time included in the packet to obtain a first hop transmission time of 80 ms. In such a case, the first hop QoS status indicates an excess delay of 10 ms.

At524, the relay UE104determines an updated QoS requirement of the second hop. For example, the QoS requirement of the second hop includes a PDB of 30 ms. Based on the delay of the first hop QoS status, the UE104determines that the updated QoS requirement of the second hop be 20 ms. In this way, the second hop makes up the excess delay of the first hop and the packet is expected to arrive at the base station102without a delay.

At526, the relay UE104determines communication resources of the second hop based on the updated QoS requirement of the second hop. For example, the relay UE104updates the QoS requirement of the second hop from 30 ms to 20 ms. The relay UE104determines that time frames closer to the current time are needed for transmitting the packet.

At528, the relay UE104transmits a communication resource request to the base station102. The communication resource request indicates the communication resources of the second hop. In some aspects, the relay UE104connects with the base station via a first channel and a second channel. The first channel corresponds to a first logical channel group and the second channel corresponds to a second logical channel group. The first logical channel group has a higher priority than the second logical channel group. For example, if the communication resource request corresponds to the first logical channel group, the base station102is more likely to grant the communication resources. Otherwise, the base station102may ignore the communication resource request. The relay UE104indicates in the communication resource request whether the communication resources correspond to the first logical channel group or the second logical channel group. The relay UE104can improve a chance of receiving the communication resources by indicating first logical channel group in the communication resource request regardless. For example, the communication resources correspond to the second logical channel group. Nevertheless, the relay UE104indicates in the communication resource request that the communication resources correspond to the first logical channel group. In some aspects, the relay UE104assigns the communication resources to the second hop without permission from the base station102.

At530, the base station102assigns the communication resources to the second hop based on the communication resource request. In some aspects, the base station102assigns based on the logical channel group corresponding to the communication resources.

At532, the base station102transmits a confirmation of the communication resources to the relay UE104. The confirmation indicates the communication resources of the communication resource request are granted. In some aspects, the confirmation indicates communication resources that are different from the communication resources of the communication resource request. For example, the base station102determines that the communication resources indicated by the communication resource request are not available or not suitable.

At534, the relay UE104forwards the packet to the target UE108using the granted communication resources. For example, the relay UE104adjusts the second hop connection based on the communication resources and the updated QoS requirement of the second hop and transmits the packet using the adjusted second hop connection.

FIG.6illustrates an example system for logical channel prioritization. Example system600is provided for the purpose of illustration only and does not limit the disclosed aspects. System600may include, but is not limited to, the UE106, the UE104, a UE602, and the base station102. Similar to the discussion above, the UE106connects with the base station102via a hop606and a hop608. The UE602also connects with the base station102via a hop604and the hop608.

According to some aspects, the UE104multiplexes packets received from the UE106and the UE602and forwards them to the base station102. The UE can multiplex the packets based on channel priorities. For example, the UE106transmits to the UE104via a first channel and the UE602transmits to the UE104via a second channel. The first channel has a higher priority than the second channel. The UE104prioritizes packets received via the first channel over packets received via the second channel. For example, the UE104multiplexes two packets received from the UE106for every packet received from the UE602. In other words, the packets from the UE106are forwarded more frequently than the packets from the UE602. In some aspects, the first channel and the second channel have a same priority. In such a case, the UE prioritizes packets based on QoS statuses. For example, the hop606is free of congestion, while the hop604is in congestion. As a result, the packets from the UE602likely have delays. For example, a first packet from the UE602arrives at the UE104with a 10 ms delay, while a second packet from the UE106arrives at the UE104on time. The UE104prioritizes the first packet because the first packet has a more urgent latency.

FIG.7illustrates an example of a side-link relay system comprising a plurality of hops. Example system700is provided for the purpose of illustration only and does not limit the disclosed aspects. System700may include, but is not limited to, the UE106, a UE702, the UE104, and the base station102. The UE106connects with the base station102via a three-hop connection710. The three-hop connection710includes a hop704, a hop706, and a hop708.

According to some aspects, the three-hop connection has one or more E2E QoS requirements. For example, as discussed above, a packet transmitted from the UE106is expected to arrive at the base station102before a time point. The UE104can split the one or more E2E QoS requirements into three parts for the hop704, the hop706, and the hop708based on link conditions of the hops. For example, the UE104splits the one or more E2E QoS requirements based on a three-dimensional splitting table. The three-dimensional splitting table is a three-dimensional version of the splitting table described in theFIG.3A, where the link conditions of three hops, instead of two hops, are included in the three-dimensional splitting table. In some aspects, the UE104can split the one or more E2E QoS requirements into N parts for an N-hop connection based on an N-dimensional splitting table, wherein N is a positive integer.

In some aspects, the UE104considers the hop704and the hop706as a single hop712. In such a case, the UE104splits the one or more E2E QoS requirements into two parts for the hop712and the hop708as discussed above inFIG.3A. For example, the hop712can be treated as the hop304and the hop708can be treated as the hop306. The UE702further splits QoS requirements of the hop712into two parts for the hop704and the hop706as discussed above inFIG.3B. For example, the hop704can be treated as the hop310and the hop706can be treated as the hop312. In such a case, the UE104and the UE702split the one or more E2E QoS requirements for hops704,706,708in two steps. In addition, the two-step splitting can be extended to split the N-hop connection. In other words, the two-hop connection ofFIG.3Aand the two-hop connection ofFIG.3Bcan be used as basic elements of the N-hop connection.

Various aspects may be implemented, for example, using one or more computer systems, such as computer system800shown inFIG.8. Computer system800may be any well-known computer capable of performing the functions described herein such as electronic devices104,106,108, and102ofFIG.1, or200ofFIG.2. Computer system800includes one or more processors (also called central processing units, or CPUs), such as a processor804. Processor804is connected to a communication infrastructure806(e.g., a bus.) Computer system800also includes user input/output device(s)803, such as monitors, keyboards, pointing devices, etc., that communicate with communication infrastructure806through user input/output interface(s)802. Computer system800also includes a main or primary memory808, such as random access memory (RAM). Main memory808may include one or more levels of cache. Main memory808has stored therein control logic (e.g., computer software) and/or data.

Computer system800may also include one or more secondary storage devices or memory810. Secondary memory810may include, for example, a hard disk drive812and/or a removable storage device or drive814. Removable storage drive814may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, tape backup device, and/or any other storage device/drive.

Removable storage drive814may interact with a removable storage unit818. Removable storage unit818includes a computer usable or readable storage device having stored thereon computer software (control logic) and/or data. Removable storage unit818may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/any other computer data storage device. Removable storage drive814reads from and/or writes to removable storage unit818in a well-known manner.

According to some aspects, secondary memory810may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system800. Such means, instrumentalities or other approaches may include, for example, a removable storage unit822and an interface820. Examples of the removable storage unit822and the interface820may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface.

Computer system800may further include a communication or network interface824. Communication interface824enables computer system800to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference number828). For example, communication interface824may allow computer system800to communicate with remote devices828over communications path826, which may be wired and/or wireless, and which may include any combination of LANs, WANs, the Internet, etc. Control logic and/or data may be transmitted to and from computer system800via communication path826.

The operations in the preceding aspects may be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding aspects may be performed in hardware, in software or both. In some aspects, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system800, main memory808, secondary memory810and removable storage units818and822, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system800), causes such data processing devices to operate as described herein.

While the disclosure has been described herein with reference to exemplary aspects for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other aspects and modifications thereto are possible, and are within the scope and spirit of the disclosure. For example, and without limiting the generality of this paragraph, aspects are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, aspects (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein.

Aspects have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. In addition, alternative aspects may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein.

The breadth and scope of the disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.