Simultaneous scheduling request transmission in dual connectivity

Briefly, in accordance with one or more embodiments, an apparatus may be configured to receive a first scheduling request transmission for a first cell group, and a second scheduling request transmission for a second cell group, determine one of the first scheduling request and the second scheduling request to have a higher priority and another one of the first scheduling request and the second scheduling request to have a lower priority, and process the scheduling request having a higher priority without processing the scheduling request having a lower priority. An apparatus may be configured to combine a configuration of a first scheduling request for a first cell group and a second configuration of a second scheduling request for a secondary cell group in a system radio bearer, and transmit the SRB to a user equipment to process the first scheduling request and the second scheduling request.

BACKGROUND

Dual Connectivity (DC) is an operation where a given user equipment (UE) consumes radio resources provided by at least two different network points connected with a non-ideal backhaul. Furthermore, each evolved Node B (eNB) involved in DC for a UE may assume different roles. Such roles do not necessarily depend on the power class of the eNB and may vary among different UEs. In the context of carrier aggregation (CA), a scheduling request (SR) is transmitted using physical uplink control channel (PUCCH) Format 1 in a primary cell (PCell) only, but is not allowed to be transmitted in a secondary cell (SCell). In DC, an SR also can be transmitted using PUCCH Format 1 in a special secondary cell (pSCell). When two SR transmissions of the PCell and a pSCell happen simultaneously, the full power of the UE may not be utilized, resulting in a negative impact for the UE especially when the UE is in a power limited scenario.

It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components and/or circuits have not been described in detail.

In the following description and/or claims, the terms coupled and/or connected, along with their derivatives, may be used. In particular embodiments, connected may be used to indicate that two or more elements are in direct physical and/or electrical contact with each other. Coupled may mean that two or more elements are in direct physical and/or electrical contact. However, coupled may also mean that two or more elements may not be in direct contact with each other, but yet may still cooperate and/or interact with each other. For example, “coupled” may mean that two or more elements do not contact each other but are indirectly joined together via another element or intermediate elements. Finally, the terms “On,” “overlying,” and “over” may be used in the following description and claims. “On,” “overlying,” and “over” may be used to indicate that two or more elements are in direct physical contact with each other. However, “over” may also mean that two or more elements are not in direct contact with each other. For example, “over” may mean that one element is above another element but not contact each other and may have another element or elements in between the two elements. Furthermore, the term “and/or” may mean “and”, it may mean “or”, it may mean “exclusive-or”, it may mean “one”, it may mean “some, but not all”, it may mean “neither”, and/or it may mean “both”, although the scope of claimed subject matter is not limited in this respect. In the following description and/or claims, the terms “comprise” and “include,” along with their derivatives, may be used and are intended as synonyms for each other.

Referring now toFIG. 1andFIG. 2, diagrams of a dual connectivity network having a higher level aggregation point and where a master enhanced Node B functions as an aggregation point, respectively, in accordance with one or more embodiments will be discussed. As shown inFIG. 1andFIG. 2, network100may implement dual connectivity wherein user equipment (UE)110simultaneously connects with a primary cell112and one or more secondary cells such as secondary cell114and/or secondary cell116. Network100may be in compliance with a Third Generation Partnership Project (3GPP) standard such as a Long Term Evolution (LTE) standard, for example LTE Release 12, and the scope of the claimed subject matter is not limited in this respect. In one or more embodiments, one or more of primary cell112, secondary cell114, or secondary cell116may comprise an evolved Node B (eNB) and/or other small cells to provide a co-channel arrangement, an inter-frequency arrangement, and/or an out of coverage of a macro cell arrangement, and the scope of the claimed subject matter is not limited in these respects. In one or more embodiments, primary cell112may be referred to as a master cell or master eNB, and the scope of the claimed subject matter is not limited in this respect. One or more cells of network100may comprise a cell group wherein a Master Cell Group may refer to a group of serving cells or nodes associated with primary cell112or Master eNB, and a Secondary Cell Group may refer to a group of servicing cells associated with a secondary eNB such as secondary cell114or secondary cell116. The Master eNB may refer to the eNB which terminates with an S1 Mobility Management Entity (S1-MME), and a Secondary eNB may be an eNB or cell that provides additional radio resources for UE110, and which is not the Master eNB. Furthermore, in a dual connectivity arrangement such as shown inFIG. 1, a bearer may be split among two or more eNBs.

As shown inFIG. 1, primary cell112, secondary cell114, and secondary cell116may be connected with a non-ideal backhaul via a higher level aggregation point122, for example via router118. Aggregation point122connects the dual connectivity network nodes to the Evolved Packet Core (EPC)120of network100. As shown inFIG. 2, primary cell112may be configured to operate as an aggregation point122for all cells for connectivity to EPC120. In one or more embodiments, when a dual connectivity arrangement is provided, the radio nodes of network100comprising the different cell groups are not allowed to transmit scheduling requests simultaneously or at any overlapped portions, for example at the subframe level or otherwise, for both power limited and non-power limited situations. A simultaneous scheduling request may be defined as when two scheduling requests transmissions occur in a same subframe wherein the scheduling requests may be fully overlapped, or when a prior scheduling transmission has occurred from a first cell group and a subsequent scheduling transmission occurs from a second cell group wherein the scheduling requests may be partially overlapped in a subframe. As will be discussed in further detail, below, various embodiments may prevent such overlapping scheduling requests, for example to allow UE110to fully utilize its transmit power.

Referring now toFIG. 3, a diagram of network protocol layers for a user equipment and for a radio access network node of the networks ofFIG. 1orFIG. 2in accordance with one or more embodiments will be discussed. In one or more embodiments, UE110as shown inFIG. 1andFIG. 2may implement network protocol layers310including physical (PHY) layer312, media access control (MAC) layer314, radio link control (RLC) layer316, packet data convergence protocol (PDCP) layer318, and/or radio resource control (RRC) layer320, although the scope of the claimed subject matter is not limited in this respect. Similarly, one or more of the nodes of network100such as primary cell112, secondary cell114, and/or secondary cell116may implement a network protocol layer322including physical (PHY) layer324, media access control (MAC) layer326, radio link control (RLC) layer328, packet data convergence protocol (PDCP) layer330, and/or radio resource control (RRC) layer332, although the scope of the claimed subject matter is not limited in this respect. A physical uplink control channel334may be provided between PHY layer312and PHY layer324to carry uplink control information between UE110and one or more nodes of network100.

In one or more embodiments, there may be two cases for handling scheduling requests. A first case may involve separate scheduling request handling in the MAC layer such as MAC layer314, for example using two different scheduling request prohibit timers (sr-ProhibitTimer) such as sr-ProhibitTimer1and sr-ProhibitTimer2. A second case may involve common scheduling request handling in the MAC layer such as MAC layer314, for example using single sr-ProhibitTimer such as sr-ProhibitTimer1. Regardless of which case is utilized, when scheduling request transmissions from two or more different cell groups having in the same frame, either by being fully overlapping or overlapping at least in part, in general only one of the scheduling requests is allowed to occur as discussed in further detail, below.

Referring now toFIG. 4, a diagram of a user equipment to receive scheduling requests from different cell groups in accordance with one or more embodiments will be discussed. In some embodiments, simultaneous scheduling request transmissions from different cell groups may be handled in the physical (PHY) layer312. In one such embodiment, a first scheduling request (SR1) may be transmitted from a first cell group such as master cell group410, and a second scheduling request (SR2) may be transmitted from a second cell group such as secondary cell group412. In such a situation, the earlier or prior scheduling request transmission has priority, and the later scheduling request transmission is made pending to be transmitted in a next available scheduling request resource. Alternatively, the scheduling request transmission (SR1) from master cell group410may have a higher priority over a scheduling request transmission from a cell group other than master cell group410, for example scheduling request transmission (SR2) from secondary cell group412. In such as case, the scheduling request transmission that is not from master cell group410is dropped, and UE110indicates to MAC layer314that the scheduling request transmission that is not from master cell group412has been dropped. MAC layer314then may instruct PHY layer312to signal a scheduling request on the physical uplink control channel (PUCCH)334to indicate that a scheduling request is pending. If a prior scheduling request transmission is from secondary cell group412and a later scheduling request transmission is from master cell group410, the scheduling request transmission (SR2) from secondary cell group412may be dropped, and the scheduling request transmission (SR1) from master cell group410may continue.

In one or more alternative embodiments, simultaneous scheduling request transmissions from different cell groups may be handled in the media access control (MAC) layer314. In some embodiments, user equipment (UE)110has a single scheduling request prohibit timer (sr-ProhibitTimer) for both master cell group410which includes the master evolved node B (MeNB) and secondary cell group412which includes a secondary evolved node B (SeNB). By having a common sr-ProhibitTimer for both master cell group410and secondary cell group412, the scheduling request for the cell group that was triggered later than a previous scheduling request schedule for another cell group automatically may be pending to a next available scheduling request opportunity. For example, assuming the following existing instructions happens per cell, an instruction to the physical (PHY) layer312to signal the signaling request on the physical uplink control channel (PUCCH)334cannot be performed for the later triggered scheduling request for another cell group. Instead, the instruction to the PHY layer312to signal the signaling request on the physical uplink control channel PUCCH334for the later triggered scheduling request for the other cell group will be performed in the next scheduling request opportunity.If no uplink shared channel (UL-SCH) resources are available for a transmission in this transmission time interval (TTI):if the user equipment (UE) has no valid physical uplink control channel (PUCCH) resource for scheduling request (SR) configured in any TTI: initiate a Random Access procedure on the primary cell (PCell) and cancel all pending SRs;else if the UE has a valid PUCCH resource for SR configured for this TTI and if this TTI is not part of a measurement gap and if sr-ProhibitTimer is not Running:if scheduling request counter (SR_COUNTER)<dsr-TransMax:increment SR_COUNTER by 1;instruct the physical layer to signal the SR on PUCCH;start the sr-ProhibitTimer.else:notify RRC to release PUCCH/SRS for all serving cells;clear any configured downlink assignments and uplink grants;initiate a Random Access procedure on the PCell and cancel all pending SRs.

In alternative embodiments, UE110may have an independent sr-ProhibitTimer for master cell group410which includes the MeNB and secondary cell group412which includes an SeNB. If UE110has a different sr-ProhibitTimer for master cell group410and secondary cell group412, UE110may perform a further step to check if there is an ongoing prior scheduling request transmission. In the event there is any ongoing prior scheduling request transmission, then a later trigger scheduling request may be made pending to a next available scheduling request opportunity, for example as shown in the sample instructions, below.If no uplink shared channel (UL-SCH) resources are available for a transmission in this transmission time interval (TTI):if the user equipment (UE) has no valid physical uplink control channel (PUCCH) resource for scheduling request configured in any TTI: initiate a Random Access procedure on the primary cell (PCell) and cancel all pending SRs;else if the UE has a valid PUCCH resource for SR configured for this TTI and if this TTI is not part of a measurement gap and if sr-ProhibitTimer is not running and if there is no on-going SR transmission for any other cell group:if SR_COUNTER<dsr-TransMax:increment SR_COUNTER by 1;instruct the physical layer to signal the SR on PUCCH;start the sr-ProhibitTimer.else:notify radio resource control (RRC) to release PUCCH/SRS for all serving cells;clear any configured downlink assignments and uplink grants;initiate a Random Access procedure on the PCell and cancel all pending SRs.

Referring now toFIG. 5, a diagram of a user equipment to receive scheduling requests from different cell groups via a system radio bearer in accordance with one or more embodiments will be discussed. In some embodiments, the handling of simultaneous scheduling resource transmissions from the different cell groups may be handled by network configuration of network100. In such embodiments, a System Radio Bearer (SRB)510may be transmitted via master cell group410, and may have the independent scheduling resource configuration for both master cell group410including the master evolved node B (eNB) and secondary cell group412including a secondary evolved Node B (SeNB). As a result, the scheduling request configurations received for both master cell group410and secondary cell group412may be signaled via the master evolved Node B (MeNB) of master cell group410. Therefore, network100is capable of ensuring that the scheduling request configurations received from different cell groups will not overlap each other for a given UE110. In such an implementation, UE110may assume there are no overlapped scheduling request resources resource between master cell group410and secondary cell group412. For example, master cell group410may receive a scheduling request SR2from secondary cell group and ensure that scheduling request SR2does not overlap its own scheduling request SR1when configured in SRB510. In one particular embodiment, it may be up to UE110to select one of the available transmissions if multiple scheduling request transmissions happen to occur simultaneously.

In alternative embodiments, network100ensures that scheduling request configurations are not configured to be overlapping among multiple cell groups. Since System Radio Bearer (SRB)510is transmitted via master cell group410, network100is capable to provide scheduling request configurations for each cell group such that the scheduling request configurations do not overlap each other. For example, master cell group410is capable of providing all scheduling requests for both itself and for secondary cell group412, and ensuring that the two scheduling request configurations to not overlap each other. In an arrangement, UE110may assume there will be no case of overlapping scheduling request transmissions.

Referring now toFIG. 6, a block diagram of an information handling system capable of handling simultaneous scheduling request transmission in dual connectivity in accordance with one or more embodiments will be discussed. Information handling system600ofFIG. 6may tangibly embody any one or more of the elements described herein, above, including for example UE110, primary cell112, secondary cell114, secondary cell116, router118, and/or EPC120, with greater or fewer components depending on the hardware specifications of the particular device. Although information handling system600represents one example of several types of computing platforms, information handling system600may include more or fewer elements and/or different arrangements of elements than shown inFIG. 6, and the scope of the claimed subject matter is not limited in these respects.

In one or more embodiments, information handling system600may include an application processor610and a baseband processor612. Application processor610may be utilized as a general-purpose processor to run applications and the various subsystems for information handling system600. Application processor610may include a single core or alternatively may include multiple processing cores wherein one or more of the cores may comprise a digital signal processor or digital signal processing (DSP) core. Furthermore, application processor610may include a graphics processor or coprocessor disposed on the same chip, or alternatively a graphics processor coupled to application processor610may comprise a separate, discrete graphics chip. Application processor610may include on board memory such as cache memory, and further may be coupled to external memory devices such as synchronous dynamic random access memory (SDRAM)614for storing and/or executing applications during operation, and NAND flash616for storing applications and/or data even when information handling system600is powered off. In one or more embodiments, instructions to operate or configure the information handling system600and/or any of its components or subsystems to operate in a manner as described herein may be stored on a article of manufacture comprising a non-transitory storage medium. In one or more embodiments, the storage medium may comprise any of the memory devices shown in and described herein, although the scope of the claimed subject matter is not limited in this respect. Baseband processor612may control the broadband radio functions for information handling system600. Baseband processor612may store code for controlling such broadband radio functions in a NOR flash618. Baseband processor612controls a wireless wide area network (WWAN) transceiver620which is used for modulating and/or demodulating broadband network signals, for example for communicating via a 3GPP LTE or LTE-Advanced network or the like.

In general, WWAN transceiver620may operate according to any one or more of the following radio communication technologies and/or standards including but not limited to: a Global System for Mobile Communications (GSM) radio communication technology, a General Packet Radio Service (GPRS) radio communication technology, an Enhanced Data Rates for GSM Evolution (EDGE) radio communication technology, and/or a Third Generation Partnership Project (3GPP) radio communication technology, for example Universal Mobile Telecommunications System (UMTS), Freedom of Multimedia Access (FOMA), 3GPP Long Term Evolution (LTE), 3GPP Long Term Evolution Advanced (LTE Advanced), Code division multiple access 2000 (CDMA2000), Cellular Digital Packet Data (CDPD), Mobitex, Third Generation (3G), Circuit Switched Data (CSD), High-Speed Circuit-Switched Data (HSCSD), Universal Mobile Telecommunications System (Third Generation) (UMTS (3G)), Wideband Code Division Multiple Access (Universal Mobile Telecommunications System) (W-CDMA (UMTS)), High Speed Packet Access (HSPA), High-Speed Downlink Packet Access (HSDPA), High-Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+), Universal Mobile Telecommunications System-Time-Division Duplex (UMTS-TDD), Time Division-Code Division Multiple Access (TD-CDMA), Time Division-Synchronous Code Division Multiple Access (TD-CDMA), 3rd Generation Partnership Project Release 8 (Pre-4th Generation) (3GPP Rel. 8 (Pre-4G)), UMTS Terrestrial Radio Access (UTRA), Evolved UMTS Terrestrial Radio Access (E-UTRA), Long Term Evolution Advanced (4th Generation) (LTE Advanced (4G)), cdmaOne (2G), Code division multiple access 2000 (Third generation) (CDMA2000 (3G)), Evolution-Data Optimized or Evolution-Data Only (EV-DO), Advanced Mobile Phone System (1st Generation) (AMPS (1G)), Total Access Communication System/Extended Total Access Communication System (TACS/ETACS), Digital AMPS (2nd Generation) (D-AMPS (2G)), Push-to-talk (PTT), Mobile Telephone System (MTS), Improved Mobile Telephone System (IMTS), Advanced Mobile Telephone System (AMTS), OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile Telephony), MTD (Swedish abbreviation for Mobiltelefonisystem D, or Mobile telephony system D), Public Automated Land Mobile (Autotel/PALM), ARP (Finnish for Autoradiopuhelin, “car radio phone”), NMT (Nordic Mobile Telephony), High capacity version of NTT (Nippon Telegraph and Telephone) (Hicap), Cellular Digital Packet Data (CDPD), Mobitex, DataTAC, Integrated Digital Enhanced Network (iDEN), Personal Digital Cellular (PDC), Circuit Switched Data (CSD), Personal Handy-phone System (PHS), Wideband Integrated Digital Enhanced Network (WiDEN), iBurst, Unlicensed Mobile Access (UMA), also referred to as also referred to as 3GPP Generic Access Network, or GAN standard), Zigbee, Bluetooth®, and/or general telemetry transceivers, and in general any type of RF circuit or RFI sensitive circuit. It should be noted that such standards may evolve over time, and/or new standards may be promulgated, and the scope of the claimed subject matter is not limited in this respect.

The WWAN transceiver620couples to one or more power amps642respectively coupled to one or more antennas624for sending and receiving radio-frequency signals via the WWAN broadband network. The baseband processor612also may control a wireless local area network (WLAN) transceiver626coupled to one or more suitable antennas628and which may be capable of communicating via a Wi-Fi, Bluetooth®, and/or an amplitude modulation (AM) or frequency modulation (FM) radio standard including an IEEE 802.11 a/b/g/n standard or the like. It should be noted that these are merely example implementations for application processor610and baseband processor612, and the scope of the claimed subject matter is not limited in these respects. For example, any one or more of SDRAM614, NAND flash616and/or NOR flash618may comprise other types of memory technology such as magnetic memory, chalcogenide memory, phase change memory, or ovonic memory, and the scope of the claimed subject matter is not limited in this respect.

In one or more embodiments, application processor610may drive a display630for displaying various information or data, and may further receive touch input from a user via a touch screen632for example via a finger or a stylus. An ambient light sensor634may be utilized to detect an amount of ambient light in which information handling system600is operating, for example to control a brightness or contrast value for display630as a function of the intensity of ambient light detected by ambient light sensor634. One or more cameras636may be utilized to capture images that are processed by application processor610and/or at least temporarily stored in NAND flash616. Furthermore, application processor may couple to a gyroscope638, accelerometer640, magnetometer642, audio coder/decoder (CODEC)644, and/or global positioning system (GPS) controller646coupled to an appropriate GPS antenna648, for detection of various environmental properties including location, movement, and/or orientation of information handling system600. Alternatively, controller646may comprise a Global Navigation Satellite System (GNSS) controller. Audio CODEC644may be coupled to one or more audio ports650to provide microphone input and speaker outputs either via internal devices and/or via external devices coupled to information handling system via the audio ports650, for example via a headphone and microphone jack. In addition, application processor610may couple to one or more input/output (I/O) transceivers652to couple to one or more I/O ports654such as a universal serial bus (USB) port, a high-definition multimedia interface (HDMI) port, a serial port, and so on. Furthermore, one or more of the I/O transceivers652may couple to one or more memory slots656for optional removable memory such as secure digital (SD) card or a subscriber identity module (SIM) card, although the scope of the claimed subject matter is not limited in these respects.

FIG. 7is an isometric view of an information handling system ofFIG. 6that optionally may include a touch screen in accordance with one or more embodiments.FIG. 7shows an example implementation of information handling system600ofFIG. 6tangibly embodied as a cellular telephone, smartphone, or tablet type device or the like. The information handling system600may comprise a housing710having a display630which may include a touch screen632for receiving tactile input control and commands via a finger716of a user and/or a via stylus718to control one or more application processors610. The housing710may house one or more components of information handling system600, for example one or more application processors610, one or more of SDRAM614, NAND flash616, NOR flash618, baseband processor612, and/or WWAN transceiver620. The information handling system600further may optionally include a physical actuator area720which may comprise a keyboard or buttons for controlling information handling system via one or more buttons or switches. The information handling system600may also include a memory port or slot656for receiving non-volatile memory such as flash memory, for example in the form of a secure digital (SD) card or a subscriber identity module (SIM) card. Optionally, the information handling system600may further include one or more speakers and/or microphones724and a connection port654for connecting the information handling system600to another electronic device, dock, display, battery charger, and so on. In addition, information handling system600may include a headphone or speaker jack728and one or more cameras636on one or more sides of the housing710. It should be noted that the information handling system600ofFIG. 7may include more or fewer elements than shown, in various arrangements, and the scope of the claimed subject matter is not limited in this respect.

Although the claimed subject matter has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and/or scope of claimed subject matter. It is believed that the subject matter pertaining to simultaneous scheduling request transmission in dual connectivity and many of its attendant utilities will be understood by the forgoing description, and it will be apparent that various changes may be made in the form, construction and/or arrangement of the components thereof without departing from the scope and/or spirit of the claimed subject matter or without sacrificing all of its material advantages, the form herein before described being merely an explanatory embodiment thereof, and/or further without providing substantial change thereto. It is the intention of the claims to encompass and/or include such changes.