The present invention relates generally to wireless communication systems, and, in particular, to an allocation of a time slot to a user of a wireless communication system.
The General Packet Radio Service (GPRS) standard provides a compatibility standard for cellular mobile telecommunications systems. The GPRS standard ensures that a mobile station (MS) operating in a GPRS system can obtain communication services when operating in a system manufactured according to the standard. To ensure compatibility, radio system parameters and call processing procedures are specified by the standard, including call processing steps that are executed by an MS and a base station serving the MS in order to establish a call and control messages that are exchanged between elements of an infrastructure that includes the base station.
In a GPRS communication system, a frequency bandwidth is divided into eight time slots (using the same frame structure as in Global System for Mobile communications (GSM)) that provide the physical communication channels and which eight time slots constitute a frame. In order for an MS to receive a data transfer, such as PS (packet switched) voice or user data and typically in a format of a Radio Downlink Control (RLC) data block, from a network serving the MS, the network must first allocate to the MS a downlink packet data channel comprising one or more time slots in a given frequency bandwith. The network then informs the MS of the allocated time slot(s) via a Packet Downlink Assignment command.
Once the time slot(s) is(are) assigned, the MS then monitors only the assigned time slot(s) in order to receive the data. The time slot remains assigned to the MS for a duration of a Temporary Block Flow (TBF) or until the MS receives a Packet Timeslot Reconfigure command. However, situations arise wherein one or more previously allocated time slots may become available for additional allocation to the MS. For example,
As a result, during a second time period, t2, corresponding to a transfer of a second block via each of allocated time slots 100-103, 105, and 107 and a third time period, t3, corresponding to a transfer of a third block via each of allocated time slots 100-103, 105, and 107, two additional time slots (time slots 104 and 106) are available for reallocation. For example, the MS allocated time slot 100 is transferred a second block 120 during the second time period and is transferred a third block 130 during the third time period. Meanwhile, time slots 104 and 106 are unused, and therefore are available for reallocation, in each of the four frames transmitted during second and third periods. However, in order to reallocate a time slot to an MS and prior to reusing the time slot, the network must first convey a Packet Timeslot Reconfigure message to the MS and then wait for an acknowledgement of the message from the MS. Such signaling consumes system resources and time, with the result that the command cannot be executed on a block-by-block basis and system resources sit idle, depicted in
Therefore, a need exists for a method and apparatus for dynamically allocating time slots that facilitates a more rapid reuse of the the time slots than permitted by the prior art.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Also, common and well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.
To address the need for a method and apparatus for dynamically allocating time slots that facilitates a more rapid reuse of the the time slots than permitted by the prior art, a communication system is provided that utilizes a Downlink Radio Link Control (RLC) data block conveyed to a mobile station (MS) via a first downlink time slot to inform the MS of an allocation of a second downlink time slot, which Downlink RLC data block is conveyed to the MS regardless of the allocation. By utilizing the Downlink RLC data block, the communication system informs the MS of the dynamically allocated time slot without the specialized messages of, and the additional bandwidth and response time consumed by, the prior art. Furthermore, when the first downlink time slot comprises a bearer channel already allocated to the MS, the system then provides for in-band signaling of the MS of the newly allocated time slot.
Generally, an embodiment of the present invention encompasses a method for dynamic allocation of a downlink time slot. The method comprises allocating a first downlink time slot to a mobile station, subsequent to allocating the first time slot, determining that a second downlink time slot is available for allocation, wherein the second time slot is different from the first time slot, allocating the second downlink time slot to the mobile station, and informing the mobile station of the allocation of the second downlink time slot via a Downlink Radio Link Control (RLC) data block.
Another embodiment of the present invention encompasses a method for dynamic allocation of a downlink time slot comprising receiving an allocation of a first downlink time slot, subsequent to receiving the allocation of the first downlink time slot, receiving a Downlink RLC data block comprising an allocation of a second downlink time slot different from the first time slot, identifying the second downlink time slot based on the received Downlink RLC data block, and monitoring each of the first downlink time slot and the second downlink time slot.
Yet another embodiment of the present invention encompasses a computer-readable medium that stores instructions for assembling a Downlink RLC data block block for conveyance by an access network to a mobile station, wherein the instructions comprise including an identifier of a downlink time slot in a header of the block.
Still another embodiment of the present invention encompasses an apparatus comprising means for allocating a first downlink time slot to a mobile station, means for determining, subsequent to allocating the first time slot, that a second downlink time slot is available for allocation, means for allocating the second downlink time slot to the mobile station; and means for conveying a Downlink RLC data block to the mobile station that informs of the allocation of the second downlink time slot.
Yet another embodiment of the present invention encompasses a mobile station comprising means for receiving an allocation of a first downlink time slot, means for receiving, subsequent to receiving the allocation of the first downlink time slot, a Downlink Radio Link Control (RLC) data block comprising an allocation of a second downlink time slot, means for identifying the second downlink time slot based on the received Downlink RLC data block, and means for monitoring each of the first downlink time slot and the second downlink time slot.
Still another embodiment of the present invention encompasses a method for in-band signaling of a time slot allocation comprising allocating a bearer channel to a mobile station, wherein the bearer channel comprises a first downlink time slot to a mobile station, subsequent to allocating the bearer channel, determining that a second downlink time slot is available for allocation, wherein the second time slot is different from the first time slot, allocating the second downlink time slot to the mobile station, and informing the mobile station of the allocation of the second downlink time slot via the bearer channel.
The present invention may be more fully described with reference to
Communication system 200 further includes multiple MSs 202, 208 (two shown), such as but not limited to a cellular phone, a radiotelephone, or a wireless communication-enabled personal computer, laptop computer, or personal digital assistant (PDA), servided by access network 220. Air interface 210 includes a downlink 212 having multiple logical and transport channels including multiple downlink traffic channels and at least one downlink signaling channel. Air interface 210 further includes an uplink 214 having multiple logical and transport channels including multiple uplink traffic channels and at least one uplink signaling channel. In communication system 200, a frequency bandwidth is divided into multiple time slots and each transport channel comprises one or more time slots of the multiple time slots.
Each of MSs 202 and 208 includes a respective processor 204, such as one or more microprocessors, microcontrollers, digital signal processors (DSPs), combinations thereof or such other devices known to those having ordinary skill in the art. The particular operations/functions of processor 204, and respectively thus of MSs 202 and 208, are determined by an execution of software instructions and routines that are stored in a respective at least one memory device 206 associated with the processor, such as random access memory (RAM), dynamic random access memory (DRAM), and/or read only memory (ROM) or equivalents thereof, that store data and programs that may be executed by the corresponding processor. Further, each of transceiver 222 and controller 230 includes a respective processor 224, 232 such as one or more microprocessors, microcontrollers, digital signal processors (DSPs), combinations thereof or such other devices known to those having ordinary skill in the art. The particular operations/functions of processors 224 and 232, and respectively thus of transceiver 222 and controller 230, are determined by an execution of software instructions and routines that are stored in a respective at least one memory device 226, 234 associated with the processor, such as random access memory (RAM), dynamic random access memory (DRAM), and/or read only memory (ROM) or equivalents thereof, that store data and programs that may be executed by the corresponding processor. Further, the particular operations/functions performed herein by access network 220 may be performed by transceiver 222, controller 230, or may be distributed between the transceiver and the controller. Each of MSs 202 and 208 and transceiver 224 further includes a transmitter (not shown) and a receiver (not shown) for wirelessly transmitting and receiving messages, such as a channel assignment message and a Radio Downlink RLC data block block.
The embodiments of the present invention preferably are implemented within MSs 202 and 208, transceiver 222, and controller 230, and more particularly with or in software programs and instructions stored in the respective at least one memory device 206, 226, 234 and respectively executed by processors 204, 224, 232. However, one of ordinary skill in the art realizes that the embodiments of the present invention alternatively may be implemented in hardware, for example, integrated circuits (ICs), application specific integrated circuits (ASICs), and the like, such as ASICs implemented in one or more of the MS 202, transceiver 222, or controller 230. Based on the present disclosure, one skilled in the art will be readily capable of producing and implementing such software and/or hardware without undo experimentation.
Communication system 200 comprises a wireless packet data communication system. In order for MSs 202 and 208 to establish a packet data connection with access network 220, each of the MSs and access network operates in accordance with well-known wireless telecommunications protocols. By operating in accordance with well-known protocols, a user of an MS can be assured that the MS will be able to communicate with access network 220 and establish a packet data communication link with an external network via the access network. Preferably, communication system 200 operates in accordance with the General Packet Radio Service (GPRS) standard, which standard specifies wireless telecommunications system operating protocols, including radio system parameters and call processing procedures. In a GPRS communication system, a frequency bandwidth is divided into eight time slots, which eight time slots constitute a frame, and a physical communication channel comprises one or more of the time slots. However, those who are of ordinary skill in the art realize that communication system 200 may operate in accordance with any one of a variety of communication systems utilizing time slots for a conveyance of voice and/or data, such as a Global System for Mobile communication (GSM) communication system, a Time Division Multiple Access (TDMA) communication system, or a Wideband Code Division Multiple Access (WCDMA) system.
Referring now to
Logic flow diagram 300 begins (302) when a call is initiated between access network 220 and a first MS serviced by the access network, such as MS 202, in accordance with well known techniques. For example, the first MS, that is, MS 202, may originate a data (GPRS) call with access network 220 or the MS may be paged for a data call by the access network. In response to the initiation of the data call, access network 220 establishes a Temporary Block Flow (TBF) in downlink 212 to support a conveyance of Radio Downlink RLC data blocks to MS 202. As part of the establishment of the TBF, access network 220 assigns (304) to MS 202 a radio resource in downlink 212 that includes a first time slot in a given frequency bandwidth. Access network 220 then conveys (306) to MS 202, and the MS receives (308) from the access network, an assignment message informing of the assigned time slot. The first time slot may comprise a dedicated signaling channel or may comprise a bearer channel used for a conveyance of bearer traffic, such as voice or user data, to the MS.
For example, as depicted in
Access network 220 then transfers data to each MS allocated a time slot 400-407 (or 500-507 with respect to
During the first time period, access network 220 further determines (310) that a second at least one time slot, allocated to an MS other than MS 202, such as a second MS 208, is available for reallocation. For example, as depicted in
In response to determining that a second at least one time slot is available for reallocation, access network 220 allocates (312) the second at least one time slot to MS 202. For example, as depicted in
Preferably, access network 220 informs MS 202 of the allocated time slot(s) by identifying the allocated time slot(s) in a header of the next block. For example,
Access network 220 then may identify the time slot allocated to the MS by including a value associated with the time slot in TFI data field 606.
For example, referring now to
Referring again to
By utilizing a Downlink RLC data block conveyed to an MS via a first downlink time slot to inform the MS of an allocation of a second downlink time slot, which Downlink RLC data block is conveyed to the MS regardless of the allocation, communication system 100 informs the MS of the dynamically allocated time slot without the specialized messages of, and the additional bandwidth consumed by, the prior art. Furthermore, when the first downlink time slot comprises a bearer channel already allocated to the MS, the system then provides for in-band signaling of the MS of the newly allocated time slot.
While the present invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes may be made and equivalents substituted for elements thereof without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather then a restrictive sense, and all such changes and substitutions are intended to be included within the scope of the present invention.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. As used herein, the terms “comprises,” “comprising,” or any variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. It is further understood that the use of relational terms, if any, such as first and second, top and bottom, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
The present application claims priority from provisional application Ser. No. 60/711,160, entitled “METHOD AND APPARATUS FOR DYNAMIC TIME SLOT ALLOCATION,” filed Aug. 25, 2005, which is commonly owned and incorporated herein by reference in its entirety.
Number | Date | Country | |
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60711160 | Aug 2005 | US |