WO2009022309A2

WO2009022309A2 - Method and apparatus for providing an adaptable resource allocation signaling scheme

Info

Publication number: WO2009022309A2
Application number: PCT/IB2008/053259
Authority: WO
Inventors: Troels Kolding; Peter Skov; Frank Frederiksen
Original assignee: Nokia Corporation; Nokia Inc.
Priority date: 2007-08-14
Filing date: 2008-08-13
Publication date: 2009-02-19
Also published as: WO2009022309A3

Abstract

An approach is providedforallocating resources.Acontrol messageis generatedfor instructing a user equipmentto enter into a multiple transmission time interval (TTI) allocation information mode in support of time domain duplex communication with a user equipment.

Description

METHOD AND APPARATUS FOR

PROVIDING AN ADAPTABLE RESOURCE

ALLOCATION SIGNALING SCHEME

RELATED APPLICATIONS

[0001] This application claims the benefit of the earlier filing date under 35 U.S. C. §119(e) of U.S. Provisional Application Serial No. 60/955,760 filed August 14, 2007, entitled "Method and Apparatus for Providing an Adaptable Resource Allocation Signaling Scheme," the entirety of which is incorporated herein by reference.

BACKGROUND

[0002] Radio communication systems, such as a wireless data networks (e.g., Third Generation Partnership Project (3 GPP) Long Term Evolution (LTE) systems, spread spectrum systems (such as Code Division Multiple Access (CDMA) networks), Time Division Multiple Access (TDMA) networks, WiMAX (Worldwide Interoperability for Microwave Access), etc.), provide users with the convenience of mobility along with a rich set of services and features. This convenience has spawned significant adoption by an ever growing number of consumers as an accepted mode of communication for business and personal uses. To promote greater adoption, the telecommunication industry, from manufacturers to service providers, has agreed at great expense and effort to develop standards for communication protocols that underlie the various services and features. One area of effort involves resource scheduling. Traditional approaches lack flexibility in the manner resource allocations are scheduled. Consequently, network performance can degrade.

SOME EXEMPLARY EMBODIMENTS

[0003] Therefore, there is a need for an approach to provide flexible resource scheduling, which can co-exist with already developed standards and protocols. [0004] According to one embodiment of the invention, a method comprises generating a control message for instructing a user equipment enter into a multiple transmission time interval (TTI) allocation information mode in support of time domain duplex communication. [0005] According to another embodiment of the invention, an apparatus comprises a processor configured to generate a control message for instructing a user equipment to enter into a multiple transmission time interval (TTI) allocation information mode in support of time domain duplex communication.

[0006] According to another embodiment of the invention, a method comprises receiving a control message indicating use of a multiple transmission time interval allocation information mode that provides for scheduling of a plurality of resource units. The method also comprises extracting new allocation information format relating to the allocation from the control message. Further, the method comprises obtaining allocation information in the new allocation information format.

[0007] According to another embodiment of the invention, an apparatus comprises logic configured to receive a control message indicating use of a multiple transmission time interval (TTI) allocation information mode that provides for scheduling of a plurality of resource units. The apparatus also comprises logic is further configured to extract new allocation information format relating to the allocation from the control message, and to obtain allocation information in the new allocation information format.

[0008] Still other aspects, features, and advantages of the invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the invention. The invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings:

[0010] FIG. 1 is a diagram of a communication system capable of providing efficient resource allocation signaling, according to various exemplary embodiments;

[0011] FIG. 2 is a ladder diagram of a signaling process to convey report formats relating to allocation scheduling, according to one embodiment;

[0012] FIG. 3 is a flowchart of a process for signaling to initiate multiple allocation scheduling, according to one embodiment;

[0013] FIG. 4 is a flowchart of a process for receiving allocation information, according to one embodiment;

[0014] FIGs. 5A and 5B are diagrams of exemplary message formats, respectively of a control message and an allocation information message, according to various exemplary embodiments;

[0015] FIGs. 6A-6D are diagrams of communication systems having exemplary long-term evolution (LTE) and E-UTRA (Evolved Universal Terrestrial Radio Access) architectures, in which the system of FIG. IA can operate to provide resource allocation, according to various exemplary embodiments;

[0016] FIG. 7 is a diagram of hardware that can be used to implement an embodiment of the invention; and

[0017] FIG. 8 is a diagram of exemplary components of a user terminal configured to operate in the systems of FIGs. 6A-6D, according to an embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENT

[0018] An apparatus, method, and software for providing scheduling of resources over multiple transmission opportunities (e.g., multiple subframes in a Time Domain Duplex mode) are disclosed. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It is apparent, however, to one skilled in the art that the embodiments of the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention.

[0019] Although the embodiments of the invention are discussed with respect to a wireless network compliant with the Third Generation Partnership Project (3 GPP) Long Term Evolution (LTE) architecture, it is recognized by one of ordinary skill in the art that the embodiments of the inventions have applicability to any type of communication system and equivalent functional capabilities.

[0020] FIG. 1 is a diagram of a communication system capable of providing efficient resource allocation signaling, according to various exemplary embodiments. As shown in FIG. 1, one or more user equipment (UEs) 101 communicate with a base station 103, which is part of an access network (e.g., 3GPP LTE (or E-UTRAN), etc.). For example, under the 3GPP LTE architecture (as shown in FIGs. 6A-6D), the base station 103 is denoted as an enhanced Node B (eNB). The UE 101 can be any type of mobile stations, such as handsets, terminals, stations, units, devices, multimedia tablets, Internet nodes, communicators, Personal Digital Assistants (PDAs) or any type of interface to the user (such as "wearable" circuitry, etc.).

[0021] The base station 103 a employs a transceiver (not shown) to exchange information with the UE 101a via one or more antennas, which transmit and receive electromagnetic signals. For instance, the base station 103 may utilize a Multiple Input Multiple Output (MIMO) antenna system for supporting the parallel transmission of independent data streams to achieve high data rates with the UE 101. The base station 103, in an exemplary embodiment, uses OFDM (Orthogonal Frequency Divisional Multiplexing) as a downlink (DL) transmission scheme and a single-carrier transmission (e.g., SC-FDMA (Single Carrier-Frequency Division Multiple Access) with cyclic prefix for the uplink (UL) transmission scheme. SC-FDMA can also be realized using a DFT-S-OFDM principle, which is detailed in 3GGP TR 25.814, entitled "Physical Layer Aspects for Evolved UTRA," v.1.5.0, May 2006 (which is incorporated herein by reference in its entirety). SC-FDMA, also referred to as Multi-User-SC-FDMA, allows multiple users to transmit simultaneously on different sub-bands.

[0022] The system 100 supports resource allocation with reduced signaling overhead. The base station 103 provides resource allocation scheduling logic 105 to grant resources for a communication link with the UE 101. The communication link, in this example, involves the downlink, which supports traffic from the network to the user, as well as an uplink for transmission of data from the UE 101 to the BS 103. In the LTE, the BS 103 maintains tight control of the transmission resources. That is, the BS 103 will, in a controlled manner, provide resources for both uplink and downlink transmissions. Typically, these are given on (1) a time- by-time basis (one grant per transmission), or (2) as semi-persistent allocations/grants, where the resources are given for a longer time period. On the user (or subscriber) side, the UE 101 utilizes a scheduling logic 107 for scheduling transmission of information stored within a transmission buffer 109.

[0023] In this example, the allocated resources involve physical resource blocks (PRB), which correspond to OFDM symbols, to provide communication between the UE 101 and the base station 103. That is, the OFDM symbols are organized into a number of physical resource blocks (PRB) that includes consecutive sub-carriers for corresponding consecutive OFDM symbols. It is noted that the sub-carriers are defined in the frequency domain, while the OFDM symbols are defined in the time domain. To indicate which physical resource blocks (or sub- carrier) are allocated to the UE 101, two exemplary schemes include: (1) bit mapping, and (2) (start, length) by using several bits indicating the start and the length of an allocation block. This signaling of the start and the length will typically use joint coding (i.e., they are signaled using one code word, which contains the information for both parts).

[0024] To ensure reliable data transmission, the system 100 of FIG. 1, in certain embodiments, uses concatenation of Forward Error Correction (FEC) coding and an Automatic Repeat Request (ARQ) protocol commonly known as Hybrid ARQ (HARQ). Automatic Repeat Request (ARQ) is an error detection mechanism using error detection logic (not shown). This mechanism permits the receiver to indicate to the transmitter that a packet or sub-packet has been received incorrectly, and thus, the receiver can request the transmitter to resend the particular packet(s). This can be accomplished with a Stop and Wait (SAW) procedure, in which the transmitter waits for a response from the receiver before sending or resending packets. The erroneous packets are used in conjunction with retransmitted packets.

[0025] By way of example, the base station 103 typically assigns at least one downlink control channel or at least one uplink control channel to UE 101 for indicating the resource allocation information. If both link directions are scheduled within the same frame, multiple control channels are transmitted simultaneously. Conventional control channels need to be larger to support multi-TTI (transmission time interval) scheduling because of the increased number of allocation options. This necessarily introduces greater overhead. For example, because the allocation resource table has a predetermined format, all user equipment must incur the increased overhead, irrespective of whether the particular user equipment is utilizing scheduling over multiple subframes. Such user equipment can also be beset with a coding penalty due to the larger allocation information; in this case, transmission power can be wasted.

[0026] The system 100, according to certain embodiments, provides a TDD (Time domain duplex) mode of 3GPP. It is noted that scheduling over multiple subframes (e.g., multi-TTI (Transmission Time Interval)) can be provided, since the scheduling functionality already considers several subframes at the same time instance (as opposed to FDD (Frequency Division Duplex) where the scheduler only considers one subframe at a time). The possible gain mechanisms, according to an exemplary embodiment, include: (1) reduction of overhead for transmitting allocation information in downlink and ACK (Acknowledgement)/NACK (Negative-Acknowledgement) reports in the uplink; and (2) increased coverage gain in the uplink.

[0027] As seen in FIG. 1, the BS 103 transmits resource allocation information to the UE 101. In turn, UE 101 can transmit data and/or control information. The control information may include scheduling information, packet decoding information, receive process information and/or feedback information. The packet decoding information, receive process information and feedback information need to be transmitted every transmission time interval (TTI). The scheduling information may be transmitted every TTI or on an as needed basis.

[0028] In one embodiment, timing rule may be specified to provide flexibility in assigning radio resources so that each resource allocation includes physical resource allocation information and duration indicating a period during which the physical resource allocation is effective. Duration may be a continuous allocation of certain TTIs to the UE 101, or a periodic allocation of resources for a certain time. For example, the duration field may be denoted by "n" TTI where "n" may have value from 1 and greater. The value of n being ' 1 ' indicates the resource is assigned for one TTI, and higher values of n indicated a corresponding smaller allocation of the physical resources in the frequency domain.

[0029] FIG. 2 is a ladder diagram of a signaling process to convey report formats relating to allocation scheduling, according to one embodiment. The system of FIG. 1, according to one embodiment, introduces specific restrictions on the allocation methodology to reduce the size (and thus improved radio performance) of the allocation information table for multi-TTI UE. A key reason for performing multi-TTI scheduling is that a user is coverage limited, and thus, will not need an allocation of more than a few resource units (RUs) or PRBs (Physical Resource Blocks). Hence, to receive a certain level of service quality it will need to be allocated more RUs (possibly continuously) in the time domain. Namely, it is recognized that efficiencies can be realized in signaling such multi-TTI allocation information.

[0030] According to one embodiment, the exact format of the allocation information for these users is signalled using a control message, e.g., RRC (or higher layer) signaling during the start-up when the UEs' radio conditions are examined (step 201). This message specifies the particular allocation information mode: single-TTI allocation or a multi-TTI allocation. The setting may be dynamically updated by means of higher layer signaling if the UEs' radio conditions improve during the call/session. In step 203, the UE 101 checks the state of the transmission buffer 109 and agrees on the reporting format for the timing rules by transmitting an appropriate response message, such as an acknowledgement message (step 205). [0031] FIG. 3 is a flowchart of a process for signaling to initiate multiple allocation scheduling, according to one embodiment. As shown, the radio condition that the user equipment is experiencing is first determined, per step 301. If the condition is not acceptable (as in the case of limited coverage), the network (i.e., base station) initiates the scheduling of resources over multiple subframes - e.g., multi-TTI (step 303). Thus, a control message is generated, as in step 305, for specifying operation in the multi-TTI allocation information mode. This control message, which can be signaled using RRC, is submitted to the UE 101, per step 305. Upon receipt of the control message, the UE 101 switches from its default mode of operation to the multi-TTI allocation information mode (step 307).

[0032] FIG. 4 is a flowchart of a process for receiving allocation information, according to one embodiment. From the UE 's perspective, in default mode, the UE 101 operates according to a single-TTI allocation information mode (step 401). The UE 101 receives the control message, e.g., RRC message, from the base station 103, and determines the new scheduling mode, per steps 403 and 405. As further described below, this information can be specified in form of a flag or another other field in the RRC message. The UE 101 can also extract information about the new allocation format, as in step 407. Subsequently, the user equipment 101 receives allocation information in this specified format (step 409), and transmits data according to the allocations (step 411).

[0033] FIGs. 5A and 5B are diagrams of exemplary message formats, respectively of a control message and an allocation information message, according to various embodiments. As mentioned in FIG. 2, an RRC (or higher layer) control message 501 is defined to instruct the UE 101 to enter either a single-TTI or a multi-TTI allocation information mode. Also, timing rules are established between the UE 101 and eNB 103 to agree on when new reporting format is taken into use (e.g., immediately, although ACK/NACK for RRC message may not have been received yet or based on some time offset signaling taking into account acknowledgement and Ll delays). The ACK/NACK messages, in one embodiment, are associated with Hybrid Automatic Repeat Request (HARQ). [0034] Additionally, some specific rules on how an uplink allocation appears (in terms of format) in the multi-TTI case compared to single-TTI case (e.g. default mode). If the multi-TTI is also supported for the downlink, similar procedures need to be followed for the downlink allocation information.

[0035] Alternatively, it is contemplated that three or more modes can be utilized; e.g., (1) single-TTI, (2) multi-TTI for users with good radio channels (e.g., no limitations and UL grant is then larger), and (3) multi-TTI users with poor radio conditions where limitations are added to reduce the size of the UL grant and to improve the coverage of the control signal transmission.

[0036] For the purposes of explanation, the multi-TTI allocation mechanism is described with respect to the uplink (e.g., transmission from the UE to the eNB). As seen in FIG. 5A, the RRC message 501 can include a flag 501a specifying whether UE is multi-TTI or single-TTI. If limitations on "multiple" allocations are enforced, more RRC modes could be defined to further yield gains on the allocation information size (e.g., 2-TTI mode, 3 -TTI mode, 4-TTI mode specifically).

[0037] Also, part of the RRC message 501 can include a specific time offset field 501b that indicates time parameters relating to the new allocation information format (taking into account RRC signalling and acknowledgement delays). For example, the time offset value can specify the duration of use of a new allocation information format.

[0038] A multi-TTI allocation message 503 is shown in FIG. 5B and includes, in an exemplary embodiment, the following fields: number of sub frames TTI field 503 a, location of subframes TTI field 503b, acknowledgement allocation field 503c, and resource unit mask field 503d. The Number of Subframe TTI field 503a indicates how many TTIs are allocated (e.g., 1- 4). It is noted that a single-TTI can be used in the sub-case when the UE 101 has only little data in its buffer 109. The Location field 503b indicates which subframes are used to create the multi-TTI allocation. In addition, the acknowledgement allocation field 503 c provides information relating to, for example, ACK/NACK HARQ information. This field 503c indicates the allocation of resources for transmitting the associated acknowledgement message(s) (e.g., ACK message or NACK message).

[0039] Furthermore, the resource unit mask field 503d specifies the masking associated with the allocated resources, e.g., PRB mask. That is, this signalling field 503d indicates which PRBs are allocated over the multi-TTI allocation. For example, if the UE 101 has 2-TTI configured, it can maximally be allocated N₂ PRBs. If the UE 101 has 3 -TTI configured, the UE 101 can maximally be allocated N₃ PRBs. Likewise, if the UE 101 has 4-TTI configured, the UE 101 can maximally be allocated N₄ PRBs, etc.

[0040] The above process adjusts the effective TTI length according to the channel conditions experienced by the UE 101. This approach differs from the conventional TTI bundling in that the L2 transport block is mapped directly to physical resources in multiple TTIs, and the transceiver (transmit/receive chain) operates with this new TTI length (which has a granularity of the current TTI length). Additionally, the approach provides the flexibility of switching between the two modes (i.e., single- and multi-TTI modes). The multi-TTI operation, in one embodiment, may be applicable to a single transport block or multiple transport blocks.

[0041] Thus, multiple TTIs with different maximum PRB allocation sizes within the same signaling scheme can be provided. It is noted that the uplink of system 100 can achieve some gain when the code block spans multiple TTIs. However, with the maximum code block size of 6144 bits, for instance, this will not be an issue. Hence, it is recognized that a multi-TTI user has a certain limited maximum data rate it can support. Based on the assumptions enumerated in the example of Table 1, to retain the single carrier properties of uplink transmission, a user equipment can be allocated to any PRB-group in the possible set (and being limited in the maximum allocated resources).

1. 4-TTI user can maximally be allocated a single PRB (10MHz, 50 options).

2. 3 -TTI user can maximally be allocated 2 PRBs (10MHz, 50+49 options).

3. 2-TTI user can maximally be allocated 3 PRBs (1 OMHz, 50+49+48 options).

4. 1-TTI user (in multi-TTI mode) can maximally be allocated 4 PRBs (10MHz, 50+49+48+47 options). Table 1

[0042] Thus, based on Table 1, the total number of bits needed to convey the above information is 9 (by calculating the states needed to indicate the PRB position and TTI assignment jointly).

[0043] Alternatively, limitations can be introduced to restrict how PRBs are used by the multi-TTI user (e.g., every second) to gain further savings.

[0044] Table 2 provides an exemplary size comparison (parameters common to the single- TTI and multi-TTI allocation information are omitted).

Table 2

[0045] The above arrangement permits use of joint coding with "number of sub-frames" and the mask to gain some further (but limited) savings. As the control channel information for the multi-TTI uplink grant is sent only once, there will be a reduction of the amount of control channels needed at the expense of a slightly lower coverage of the multi-TTI control channel. This changed coverage can be compensated by aggregating control channel elements to obtain a lower effective code rate of the uplink control channel in the downlink. [0046] As explained, the above arrangement and associated processes can be effected in an LTE system. Such a system is now explained. However, it is recognized that other communication architectures can be utilized as well.

[0047] FIGs. 6A-6D are diagrams of communication systems having exemplary long-term evolution (LTE) architectures, in which the user equipment (UE) and the base station of FIG. 1 can operate, according to various exemplary embodiments. By way of example (shown in FIG. 6A), a base station (e.g., destination node) and a user equipment (UE) (e.g., source node) can communicate in system 600 using any access scheme, such as Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Orthogonal Frequency Division Multiple Access (OFDMA) or Single Carrier Frequency Division Multiple Access (FDMA) (SC-FDMA) or a combination of thereof. In an exemplary embodiment, both uplink and downlink can utilize WCDMA. In another exemplary embodiment, uplink utilizes SC-FDMA, while downlink utilizes OFDMA.

[0048] The communication system 600 is compliant with 3GPP LTE, entitled "Long Term Evolution of the 3GPP Radio Technology" (which is incorporated herein by reference in its entirety). As shown in FIG. 6A, one or more user equipment (UEs) communicate with a network equipment, such as a base station 103, which is part of an access network (e.g., WiMAX (Worldwide Interoperability for Microwave Access), 3GPP LTE (or E-UTRAN), etc.). Under the 3GPP LTE architecture, base station 103 is denoted as an enhanced Node B (eNB).

[0049] MME (Mobile Management Entity)/Serving Gateways 601 are connected to the eNBs 103 in a full or partial mesh configuration using tunneling over a packet transport network (e.g., Internet Protocol (IP) network) 603. Exemplary functions of the MME/Serving GW 601 include distribution of paging messages to the eNBs 103, termination of U-plane packets for paging reasons, and switching of U-plane for support of UE mobility. Since the GWs 601 serve as a gateway to external networks, e.g., the Internet or private networks 603, the GWs 601 include an Access, Authorization and Accounting system (AAA) 605 to securely determine the identity and privileges of a user and to track each user's activities. Namely, the MME Serving Gateway 601 is the key control-node for the LTE access-network and is responsible for idle mode UE tracking and paging procedure including retransmissions. Also, the MME 601 is involved in the bearer activation/deactivation process and is responsible for selecting the SGW (Serving Gateway) for a UE at the initial attach and at time of intra-LTE handover involving Core Network (CN) node relocation.

[0050] A more detailed description of the LTE interface is provided in 3GPP TR 25.813, entitled "E-UTRA and E-UTRAN: Radio Interface Protocol Aspects," which is incorporated herein by reference in its entirety.

[0051] In FIG. 6B, a communication system 602 supports GERAN (GSM/EDGE radio access) 604, and UTRAN 606 based access networks, E-UTRAN 612 and non-3GPP (not shown) based access networks, and is more fully described in TR 23.882, which is incorporated herein by reference in its entirety. A key feature of this system is the separation of the network entity that performs control-plane functionality (MME 608) from the network entity that performs bearer-plane functionality (Serving Gateway 610) with a well defined open interface between them SI l. Since E-UTRAN 612 provides higher bandwidths to enable new services as well as to improve existing ones, separation of MME 608 from Serving Gateway 610 implies that Serving Gateway 610 can be based on a platform optimized for signaling transactions. This scheme enables selection of more cost-effective platforms for, as well as independent scaling of, each of these two elements. Service providers can also select optimized topological locations of Serving Gateways 610 within the network independent of the locations of MMEs 608 in order to reduce optimized bandwidth latencies and avoid concentrated points of failure.

[0052] As seen in FIG. 6B, the E-UTRAN (e.g., eNB) 612 interfaces with UE 101 via LTE- Uu. The E-UTRAN 612 supports LTE air interface and includes functions for radio resource control (RRC) functionality corresponding to the control plane MME 608. The E-UTRAN 612 also performs a variety of functions including radio resource management, admission control, scheduling, enforcement of negotiated uplink (UL) QoS (Quality of Service), cell information broadcast, ciphering/deciphering of user, compression/decompression of downlink and uplink user plane packet headers and Packet Data Convergence Protocol (PDCP). [0053] The MME 608, as a key control node, is responsible for managing mobility UE identifies and security parameters and paging procedure including retransmissions. The MME 608 is involved in the bearer activation/deactivation process and is also responsible for choosing Serving Gateway 610 for the UE 101. MME 608 functions include Non Access Stratum (NAS) signaling and related security. MME 608 checks the authorization of the UE 101 to camp on the service provider's Public Land Mobile Network (PLMN) and enforces UE 101 roaming restrictions. The MME 608 also provides the control plane function for mobility between LTE and 2G/3G access networks with the S3 interface terminating at the MME 608 from the SGSN (Serving GPRS Support Node) 614.

[0054] The SGSN 614 is responsible for the delivery of data packets from and to the mobile stations within its geographical service area. Its tasks include packet routing and transfer, mobility management, logical link management, and authentication and charging functions. The S6a interface enables transfer of subscription and authentication data for authenticating/authorizing user access to the evolved system (AAA interface) between MME 608 and HSS (Home Subscriber Server) 616. The SlO interface between MMEs 608 provides MME relocation and MME 608 to MME 608 information transfer. The Serving Gateway 610 is the node that terminates the interface towards the E-UTRAN 612 via Sl-U.

[0055] The Sl-U interface provides a per bearer user plane tunneling between the E-UTRAN 612 and Serving Gateway 610. It contains support for path switching during handover between eNBs 103. The S4 interface provides the user plane with related control and mobility support between SGSN 614 and the 3GPP Anchor function of Serving Gateway 610.

[0056] The S12 is an interface between UTRAN 606 and Serving Gateway 610. Packet Data Network (PDN) Gateway 618 provides connectivity to the UE 101 to external packet data networks by being the point of exit and entry of traffic for the UE 101. The PDN Gateway 618 performs policy enforcement, packet filtering for each user, charging support, lawful interception and packet screening. Another role of the PDN Gateway 618 is to act as the anchor for mobility between 3GPP and non-3 GPP technologies such as WiMax and 3GPP2 (CDMA IX and EvDO (Evolution Data Only)). [0057] The S7 interface provides transfer of QoS policy and charging rules from PCRF (Policy and Charging Role Function) 620 to Policy and Charging Enforcement Function (PCEF) in the PDN Gateway 618. The SGi interface is the interface between the PDN Gateway and the operator's IP services including packet data network 622. Packet data network 622 may be an operator external public or private packet data network or an intra operator packet data network, e.g., for provision of IMS (IP Multimedia Subsystem) services. Rx+ is the interface between the PCRF and the packet data network 622.

[0058] As seen in FIG. 6C, the eNB 103 utilizes an E-UTRA (Evolved Universal Terrestrial Radio Access) (user plane, e.g., RLC (Radio Link Control) 615, MAC (Media Access Control) 617, and PHY (Physical) 619, as well as a control plane (e.g., RRC 621)). The eNB 103 also includes the following functions: Inter Cell RRM (Radio Resource Management) 623, Connection Mobility Control 625, RB (Radio Bearer) Control 627, Radio Admission Control 629, eNB Measurement Configuration and Provision 631, and Dynamic Resource Allocation (Scheduler) 633.

[0059] The eNB 103 communicates with the aGW 601 (Access Gateway) via an Sl interface. The aGW 601 includes a User Plane 601a and a Control plane 601b. The control plane 601b provides the following components: SAE (System Architecture Evolution) Bearer Control 635 and MM (Mobile Management) Entity 637. The user plane 601b includes a PDCP (Packet Data Convergence Protocol) 639 and a user plane functions 641. It is noted that the functionality of the aGW 601 can also be provided by a combination of a serving gateway (SGW) and a packet data network (PDN) GW. The aGW 601 can also interface with a packet network, such as the Internet 643.

[0060] In an alternative embodiment, as shown in FIG. 6D, the PDCP (Packet Data Convergence Protocol) functionality can reside in the eNB 103 rather than the GW 601. Other than this PDCP capability, the eNB functions of FIG. 6C are also provided in this architecture.

[0061] In the system of FIG. 6D, a functional split between E-UTRAN and EPC (Evolved Packet Core) is provided. In this example, radio protocol architecture of E-UTRAN is provided for the user plane and the control plane. A more detailed description of the architecture is provided in 3GPP TS 86.300.

[0062] The eNB 103 interfaces via the Sl to the Serving Gateway 645, which includes a Mobility Anchoring function 647. According to this architecture, the MME (Mobility Management Entity) 649 provides SAE (System Architecture Evolution) Bearer Control 651, Idle State Mobility Handling 653, and NAS (Non-Access Stratum) Security 655.

[0063] One of ordinary skill in the art would recognize that the processes for resource scheduling may be implemented via software, hardware (e.g., general processor, Digital Signal Processing (DSP) chip, an Application Specific Integrated Circuit (ASIC), Field Programmable Gate Arrays (FPGAs), etc.), firmware, or a combination thereof. Such exemplary hardware for performing the described functions is detailed below with respect to FIG. 7.

[0064] FIG. 7 illustrates exemplary hardware upon which various embodiments of the invention can be implemented. A computing system 700 includes a bus 701 or other communication mechanism for communicating information and a processor 703 coupled to the bus 701 for processing information. The computing system 700 also includes main memory 705, such as a random access memory (RAM) or other dynamic storage device, coupled to the bus 701 for storing information and instructions to be executed by the processor 703. Main memory 705 can also be used for storing temporary variables or other intermediate information during execution of instructions by the processor 703. The computing system 700 may further include a read only memory (ROM) 707 or other static storage device coupled to the bus 701 for storing static information and instructions for the processor 703. A storage device 709, such as a magnetic disk or optical disk, is coupled to the bus 701 for persistently storing information and instructions.

[0065] The computing system 700 may be coupled via the bus 701 to a display 711, such as a liquid crystal display, or active matrix display, for displaying information to a user. An input device 713, such as a keyboard including alphanumeric and other keys, may be coupled to the bus 701 for communicating information and command selections to the processor 703. The input device 713 can include a cursor control, such as a mouse, a trackball, or cursor direction keys, for communicating direction information and command selections to the processor 703 and for controlling cursor movement on the display 711.

[0066] According to various embodiments of the invention, the processes described herein can be provided by the computing system 700 in response to the processor 703 executing an arrangement of instructions contained in main memory 705. Such instructions can be read into main memory 705 from another computer-readable medium, such as the storage device 709. Execution of the arrangement of instructions contained in main memory 705 causes the processor 703 to perform the process steps described herein. One or more processors in a multi-processing arrangement may also be employed to execute the instructions contained in main memory 705. In alternative embodiments, hard- wired circuitry may be used in place of or in combination with software instructions to implement the embodiment of the invention. In another example, reconfigurable hardware such as Field Programmable Gate Arrays (FPGAs) can be used, in which the functionality and connection topology of its logic gates are customizable at run-time, typically by programming memory look up tables. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.

[0067] The computing system 700 also includes at least one communication interface 715 coupled to bus 701. The communication interface 715 provides a two-way data communication coupling to a network link (not shown). The communication interface 715 sends and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. Further, the communication interface 715 can include peripheral interface devices, such as a Universal Serial Bus (USB) interface, a PCMCIA (Personal Computer Memory Card International Association) interface, etc.

[0068] The processor 703 may execute the transmitted code while being received and/or store the code in the storage device 709, or other non-volatile storage for later execution. In this manner, the computing system 700 may obtain application code in the form of a carrier wave.

[0069] The term "computer-readable medium" as used herein refers to any medium that participates in providing instructions to the processor 703 for execution. Such a medium may take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as the storage device 709. Volatile media include dynamic memory, such as main memory 705. Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise the bus 701. Transmission media can also take the form of acoustic, optical, or electromagnetic waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, CDRW, DVD, any other optical medium, punch cards, paper tape, optical mark sheets, any other physical medium with patterns of holes or other optically recognizable indicia, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can read.

[0070] Various forms of computer-readable media may be involved in providing instructions to a processor for execution. For example, the instructions for carrying out at least part of the invention may initially be borne on a magnetic disk of a remote computer. In such a scenario, the remote computer loads the instructions into main memory and sends the instructions over a telephone line using a modem. A modem of a local system receives the data on the telephone line and uses an infrared transmitter to convert the data to an infrared signal and transmit the infrared signal to a portable computing device, such as a personal digital assistant (PDA) or a laptop. An infrared detector on the portable computing device receives the information and instructions borne by the infrared signal and places the data on a bus. The bus conveys the data to main memory, from which a processor retrieves and executes the instructions. The instructions received by main memory can optionally be stored on storage device either before or after execution by processor.

[0071] FIG. 8 is a diagram of exemplary components of a user terminal configured to operate in the systems of FIGs. 6A-6D, according to an embodiment of the invention. A user terminal 800 includes an antenna system 801 (which can utilize multiple antennas) to receive and transmit signals. The antenna system 801 is coupled to radio circuitry 803, which includes multiple transmitters 805 and receivers 807. The radio circuitry encompasses all of the Radio Frequency (RF) circuitry as well as base-band processing circuitry. As shown, layer- 1 (Ll) and layer-2 (L2) processing are provided by units 809 and 811, respectively. Optionally, layer-3 functions can be provided (not shown). Module 813 executes all Medium Access Control (MAC) layer functions. A timing and calibration module 815 maintains proper timing by interfacing, for example, an external timing reference (not shown). Additionally, a processor 817 is included. Under this scenario, the user terminal 800 communicates with a computing device 819, which can be a personal computer, work station, a Personal Digital Assistant (PDA), web appliance, cellular phone, etc.

[0072] While the invention has been described in connection with a number of embodiments and implementations, the invention is not so limited but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims. Although features of the invention are expressed in certain combinations among the claims, it is contemplated that these features can be arranged in any combination and order.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method comprising: generating a control message for instructing a user equipment to enter into a multiple transmission time interval (TTI) allocation information mode in support of time domain duplex communication.

2. A method according to claim 1, wherein the control message further specifies a time offset value indicating duration of use of a new allocation information format associated with the multiple transmission time interval allocation information mode.

3. A method according to claim 2, further comprising: transmitting allocation information according to the new allocation information format.

4. A method according to claim 2, wherein the new allocation information format specifies number of TTI allocations, location of the TTI allocations, and allocation of associated acknowledgement messages.

5. A method according to claim 1, wherein the control message is generated according to a RRC (Radio Resource Control) signaling protocol.

6. A method according to claim 1, wherein the user equipment is a mobile station, and the method further comprises: determining whether the user equipment is within a limited coverage area, wherein the control message is generated based on the determination.

7. A method according to claim 1, further comprising: signaling the user equipment to dynamically change the format of the allocation information based on the radio condition experienced by the user equipment.

8. A method according to claim 1, wherein the time domain duplex communication is established in a radio network that has a long term evolution (LTE)-compliant architecture.

9. A computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause the one or more processors to perform the method of claim 1.

10. An apparatus comprising: a processor configured to generate a control message for instructing a user equipment to enter into a multiple transmission time interval (TTI) allocation information mode in support of time domain duplex communication.

11. An apparatus according to claim 10, wherein the control message further specifies a time offset value indicating duration of use of a new allocation information format associated with the multiple transmission time interval allocation information mode.

12. An apparatus according to claim 11, further comprising: a transceiver configured to transmit allocation information according to the new allocation information format.

13. An apparatus according to claim 11, wherein the new allocation information format specifies number of TTI allocations, location of the TTI allocations, and allocation of associated acknowledgement messages.

14. An apparatus according to claim 10, wherein the control message is generated according to a RRC (Radio Resource Control) signaling protocol.

15. An apparatus according to claim 10, wherein the user equipment is a mobile station, and the processor is further configured to determine whether the user equipment is within a limited coverage area, wherein the control message is generated based on the determination.

16. An apparatus according to claim 10, wherein the processor is further configured to generate a signal for transmission to the user equipment to dynamically change the format of the allocation information based on the radio condition experienced by the user equipment.

17. An apparatus according to claim 10, wherein the time domain duplex communication is established in a radio network that has a long term evolution (LTE)-compliant architecture.

18. An apparatus according to claim 10, wherein the apparatus is a base station, and the user equipment is a handset.

19. A method comprising : receiving a control message indicating use of a multiple transmission time interval allocation information mode that provides for scheduling of a plurality of resource units; extracting new allocation information format relating to the allocation from the control message; and obtaining allocation information in the new allocation information format.

20. A method according to claim 19, wherein the new allocation information format specifies number of TTI allocations, location of the TTI allocations, and allocation of associated acknowledgement messages.

21. A computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause the one or more processors to perform the method of claim 19.

22. An apparatus comprising: logic configured to receive a control message indicating use of a multiple transmission time interval (TTI) allocation information mode that provides for scheduling of a plurality of resource units, wherein the logic is further configured to extract new allocation information format relating to the allocation from the control message, and to obtain allocation information in the new allocation information format.

23. An apparatus according to claim 22, wherein the new allocation information format specifies number of TTI allocations, location of the TTI allocations, and allocation of associated acknowledgement messages.