The exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer program products, and relate as well to techniques to provide multimedia services in a wireless communication system.
The following abbreviations are herewith defined:
A proposed communication system known as evolved UTRAN (E-UTRAN, also referred to as UTRAN-LTE or as E-UTRA) is currently under discussion within the 3GPP. The current working assumption is that the DL access technique will be OFDM, and the UL access technique will be SC-FDMA using cyclic prefix to achieve UL inter-user orthogonality.
One specification of interest is 3GPP TS 36.300, V8.2.0 (2007-09), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Access Network (E-UTRAN); Overall description; Stage 2 (Release 8), which is incorporated by reference herein.
Reference can be made to 3GPP TS 36.300, V8.2.0 (2007-09), generally in Section 15.1.2, “E-MBMS User Plane Protocol Architecture”, where the SYNC protocol is defined as a protocol to carry additional information that enable eNBs to identify the timing for radio frame transmission and detect packet loss.
Reference can also be made to 3GPP TS 36.300, V8.2.0 (2007-09), generally in Section 15.3, “MBMS Transmission”, and more specifically in Section 15.3.3, “Multi-cell transmission”, where the following features are described.
Multi-cell transmission of MBMS is characterized by:
Synchronous transmission of MBMS within its MBSFN Area;
Combining of MBMS transmission from multiple cells is supported;
MTCH and MCCH are mapped on MCH for p-t-m transmission;
The MBSFN Transmitting, Advertising, and Reserved cells are either semi-statically configured e.g. by O&M (MBMS-dedicated cell or MBMS/Unicast-mixed cell), or are dynamically adjusted (MBMS/unicast-mixed cell) e.g. based on counting mechanisms (for future study).
The MBSFN Synchronization Area is semi-statically configured e.g. by O&M. The MBSFN Area can be semi-statically configured by O&M or (for future study) dynamically configured by MCE.
Scheduling is done by the MBMS Coordination Entity (MCE).
AMC based on non-AS level feedback is also for future study.
A carrier frequency may support more than one MCH, where the physical resource allocation to a specific MCH is made by specifying a pattern of subframes, not necessarily adjacent in time, to that MCH. This pattern is called a MCH Subframe Allocation Pattern (MSAP). Multiple MBMS services can be mapped to the same MCH and one MCH contains data belonging to only one SFA. Whether there is a 1-to-1 mapping between MCH and SFA is also for future study.
The content synchronization for multi-cell transmission is provided by the following principles:
All eNBs in a given MBSFN Synchronization Area have a synchronized radio frame timing such that the radio frames are transmitted at the same time.
All eNBs have the same configuration of RLC/MAC/PHY for each MBMS service. These may be indicated in advance by the MCE (possibly, or perhaps by the O&M).
An E-MBMS GW sends/broadcasts MBMS packet with the SYNC protocol to each eNB transmitting the service.
The SYNC protocol provides additional information so that the eNBs identify the transmission radio frame(s). The E-MBMS GW does not need accurate knowledge of radio resource allocation in terms of exact time division (e.g. exact start time of the radio frame transmission).
The eNB buffers MBMS packet and waits for the transmission timing indicated in the SYNC protocol.
The segmentation/concatenation is needed for MBMS packets and should be totally up to the RLC/MAC layer in eNB.
The SYNC protocol provides means to detect packet loss(es) and supports a recovery mechanism robust against loss of consecutive PDU packets (MBMS Packets with SYNC Header).
For the packet loss case the transmission of radio blocks potentially impacted by the lost packet should be muted.
The mechanism supports indication or detection of MBMS data burst termination (e.g., to identify and alternately use available spare resources related to pauses in the MBMS PDU data flow).
Having thus provided an overview of features of the multi-cell transmission of MBMS, as presently envisioned, it can be noted that in general MBMS has been defined as a unidirectional point-to-multipoint IP datacast service that may be used to transfer, for example, video and audio clips, and that can provide real time and high rate streaming to an audience.
As was noted above, MBMS operation in E-UTRAN (eMBMS) is currently being specified in 3GPP. One of the topics addressed thus far is a SFN operational mode of eMBMS. In the SFN mode, and for a case of multi-cell operation, all cells are to transmit exactly the same content over the air interface, with exactly the same format regarding the Layer 1 (physical layer) resources (TBs, their content and coding).
However, the problems that would arise in the MBMS SFN mode of operation are at least two-fold. First, the problem arises as to how to ensure that the TBs, their length, coding and content, is the same in each radio cell when transmitted to the UEs. If the TBs or their content were to be different, then the reception at the UE side would suffer at least due to the increased interference in such a case. That is, if the neighbor eNBs/cells are transmitting a different “bit stream” with the same radio resource at the same time, this condition will be perceived as an interfering signal in the UE receiver that will increase the interference level. The particular challenge here is that the data units received from the network that are processed into Transport Blocks can be of variable length.
A second problem that arises is how to ensure the SFN mode of operation without any significant impact on the E-UTRAN architecture, that thus far has been designed for unicast (i.e., not MBMS) operation.
It has been suggested that eMBMS may require a centralized logical element in the E-UTRAN architecture, where the radio interface functions related to TB formation would occur. The use of this approach would presumably ensure that all radio cells in the SFN mode of operation would receive similar TBs for any given eMBMS data stream, and the TBs would not be formed autonomously as is the case for, by example, unicast traffic.
However, the introduction of such a centralized element in the E-UTRAN architecture would be a major departure from the “flat”, RNC-less architecture for unicast traffic. In the flat architecture of the E-UTRAN system there would ideally not be any centralized radio network element, and instead all radio network processing, especially in the user plane, would reside in the LTE base station, i.e., in the eNodeBs (eNBs).
Further reference with regard to certain MBMS features can be made to, for example,
3GPP TSG-RAN WG 3 Meeting #53bis, R3-061534, Seoul, Korea, 10 Oct.-13 Oct., 2006, “Architecture for Content Synchronisation”, Alcatel;
3GPP TSG-RAN3#54, R3-061661, Riga, Latvia, 6-10 Nov. 2006, “Content synchronization scheme with segmentation and concatenation in eNB”, NTT DoCoMo; and
3GPP TSG RAN WG3 #54 R3-061681, Riga, Latvia, 6-10 Nov. 2006, “LTE MBMS SFN: Super-frame Based Content Synchronisation”, IPWireless.
The foregoing and other problems are overcome by the use of the exemplary embodiments of this invention.
In one aspect thereof the exemplary embodiments of this invention provide a method that includes receiving and storing a set of rules; receiving an initial data unit that comprises an indication of a time to start a downlink multicast broadcast multimedia service transmission; forming transport blocks corresponding to the data unit in accordance with the stored set of rules; and transmitting at the indicated time the transport blocks formed in accordance with the rules.
In another aspect thereof the exemplary embodiments of this invention provide an apparatus that comprises a memory configurable to and store a set of rules; a unit configurable to receive an initial data unit that comprises an indication of a time to begin a downlink multicast broadcast multimedia service transmission and a processor configurable to form transport blocks corresponding to the data unit in accordance with the stored set of rules; and a wireless transmitter to transmit the transport blocks at the indicated time in cooperation with transport blocks transmitted by other apparatus using a same transmission frequency.
In another aspect thereof the exemplary embodiments of this invention provide an apparatus that comprises means for storing a set of rules; means for receiving an initial data unit that comprises an indication of a time to begin a downlink multicast broadcast multimedia service transmission and for forming transport blocks corresponding to the data unit in accordance with the stored set of rules; and means for transmitting the transport blocks at the indicated time in cooperation with transport blocks transmitted by other apparatus using a same transmission frequency.
In a further aspect thereof the exemplary embodiments of this invention provide a method that includes creating a table of data unit processing rules in a wireless network node and distributing the table of data unit processing rules to individual ones of a plurality of base stations that form a part of a single frequency network established to transmit multicast broadcast multimedia service transmissions to at least one user equipment.
In yet another aspect thereof the exemplary embodiments of this invention provide an apparatus that comprises means for creating a table of data unit processing rules at a wireless network node and means for distributing the table of data unit processing rules to individual ones of a plurality of base stations that form a part of a single frequency network established to transmit multicast broadcast multimedia service transmissions to at least one user equipment.
In the attached Drawing Figures:
Reference is made first to
In practice there will be a plurality of eNBs 12, as shown in
In general, the various embodiments of the UE 10 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.
The MEMs 10B, 12B and 14B may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 10A, 12A and 14A may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples.
The use of the exemplary embodiments of this invention in the system 1 of
It is noted that the number of rules in the rule set 12E can vary based on the level of optimization desired, as well as based on other criteria.
In the use of the exemplary embodiments of this invention, and referring to
At Block 4C the TBs that are formed based on the rules set 12E are then transmitted to the UE 10 based on the timing information associated with the originally received data unit.
Further in accordance with the exemplary embodiments of this invention, and referring to
The various blocks shown in
One significant advantage that may be realized by the use of this invention is that it allows a flat E-UTRAN radio network architecture to be used for provisioning eMBMS, thus allowing a similar architecture for both unicast traffic (an architecture already defined in 3GPP) and MBMS traffic. The ability to perform the SFN operation without the use of the exemplary embodiments of this invention may not be feasible, as the similar treatment of data units by the eNBs 12 in all cells cannot be ensured.
In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
As such, it should be appreciated that at least some aspects of the exemplary embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be fabricated on a semiconductor substrate. Such software tools can automatically route conductors and locate components on a semiconductor substrate using well established rules of design, as well as libraries of pre-stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility for fabrication as one or more integrated circuit devices.
It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.
Various modifications and adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention.
For example, while described in the context of the LTE (E-UTRAN) wireless communication system, the various exemplary aspects of this invention may be employed in other types of wireless communications systems where it is desirable to provide a downlink multicast broadcast multimedia service, or a similar type of service.
Furthermore, some of the features of the various non-limiting and exemplary embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.
This patent application claims priority under 35 U.S.C. §119(e) from Provisional Patent Application No. 60/850,728, filed Oct. 10, 2006, the disclosure of which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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60850728 | Oct 2006 | US |