Description

Nowadays, there are two WiMAX-related standardization organizations: IEEE **2.*6 Working Group and WiMAX Forum. The IEEE**2.*6 Working Group aims to create standards for broadband wireless access, while the WiMAX Forum is an industry-led non-profitable organization committed to promoting and certifying interoperable WiMAX products.
As the first company to put forward the concept of carrier-grade WiMAX network, ZTE has always been devoting itself to the development of WiMAX standards. The company has already submitted more than **0 proposals to the IEEE **2.*6 Working Group covering control channel, frame structure, multi-hop relay, Femto Base Station (BS), mobility management, etc. Additionally, as one of *5 board members of the WiMAX Forum, ZTE has submitted over **0 proposals to the forum involving hot topics such as MultiCast BroadCast Service (MCBCS), Emergency Service (ES), IP Multi-media Subsystem (IMS), Policy and Charge Control (PCC), and Simple IP.
Due to their outstanding contribution to the setting of WiMAX standards, many experts from ZTE are honored to lead the standardization process. Among them, Tricci So is elected as Chairman of the MCBCS Working Group in the WiMAX Forum; Jerry Chow is invited to be Chairman of the IEEE **2.*6m E-MBS Rapporteur Group; Mary Chion is appointed as Chairman of the IEEE **2.*6m Handoff E-MBS Rapporteur Group.

MCBCS
The unicast network offers personalized contents to end users on a one-to-one basis, with each user occupying independent spectrum and network resource. However, this resource could be shared by all users when the same content is delivered. MCBCS can effectively utilize the limited resources to broadcast the same content to multiple users. Mobile TV is a typical application of MCBCS. As the spectrum resource is limited, and most of the users\' requirements can be classified, MCBCS is receiving increasing attention in the industry. 
At present, a MCBCS subgroup has been established in the Network Working Group (NGW) Release 1.5 of the WiMAX Forum and it plans to finish the related standardization work in two phases. Broadcast and static multicast service will be provided in the first phase and dynamic multicast service will be supported in the second phase. The basic technical documents of the first phase have been finished, which specifies the MCBCS network architecture, service initiation, service setup/release procedures, mobility management, power saving support, data transmission, and data synchronization. They are in the Verification and Validation (V&V) comments resolution process and will be released in the Q1 of ***9. 
Being the leader of the MCBCS subgroup, ZTE has been undertaking great responsibilities and has submitted proposals covering almost all key technical points. Despite of the fierce arguments and a wide divergence of views from different operators and equipment vendors, ZTE managed to bring different opinions into agreement and keep the standardization work on schedule.

Multi-Hop Relay
All BSs of current wireless communications system need the support of fixed lines, and their coverage is relatively fixed. Because of the barriers on the transmission routes or long distance transmission, blind areas or edge areas with serious signal attenuation are formed. To expand the coverage and improve the service quality for the edge users, the IEEE **2.*6 Working Group proposes the multi-hop relay technology, in which one or more wireless Relay Stations (RSs) are added into the system to decode or demodulate the received signals into source signals for storage and processing. After being coded and modulated, the source signals are sent to the receiver.  
The IEEE **2.*6 Working Group has two subgroups related to multi-hop relay: Relay Task Group (RTG) and IEEE **2.*6m Task Group (TGm). RTG aims to develop IEEE **2.*6j standards, hoping to introduce the multi-hop relay technology based on IEEE **2.*6e standards. The IEEE **2.*6j D8 is currently under sponsor ballot and the IEEE **2.*6j D9, which will be finished in February ***9, will integrate the IEEE **2.*6e to form a complete IEEE **2.*6 Rev2 standard. The objective of TGm is to provide higher mobility and transmission rate to fulfill the IMT-Advanced requirements. A Relay Rapporteur Group is established in TGm to draft system description related to the IEEE **2.*6m multi-hop relay. 
The system topology will be changed due to the adding of wireless RSs. Therefore, it is necessary to intelligently adjust the topological relation and configuration between the RSs and BSs. Specifically, the impact on the system from connection, release and handoff of the RSs should be taken into consideration, and full use of the RSs should be made to improve data transmission efficiency. For example, when a RS performs handoff from the serving BS to a target BS, it must allow its connected RSs or mobile terminals to be handoffed first to the target BS. Another case is that the BS must inform the RS to transmit the corresponding data delay so that it can transmit MCBCS data synchronously with the BS. One more example is that the RS can directly forward data for transmission between its connected two mobile terminals without transmitting them to the BS, which improves data transmission efficiency. 
ZTE has submitted more than *0 relay-related proposals to RTG and TGm, with content covering data transmission methods, MCBCS, relay data format, as well as connection, release and handoff of the RSs.