Industrial Technology Research Institute

Telcodia Applied Research Center Taiwan Co.

Yen-Cheng Lai

Phone Lin

Chung-Min Chen

Lu-Tsung Chang

Wanjiun Liao

Jason Yi-Bing Lin

In a Vehicular Ad Hoc Network (VANET) a hybrid method combines SDMA (Space Division Multiple Access) and dynamic TDMA (Time Division Multiple Access) that divides the roadway into regions (whose size is larger than the SDMA unit) where each region is allocated a pool of radio channels based on SDMA and may contain a limited number of vehicles. Vehicles within the same region compete for and access the channels using dynamic TDMA. A channel allocation scheme that maps the pool of channels to the regions such that when a vehicle acquires multiple channels (time slots) in a region, the intervals among the channels are as uniform as possible, thus minimizing the waiting time of the messages to be broadcast by the vehicle, which is critical for safety related applications. This solution is referred to as R-SDMA (Region based SDMA).

Region-based clustering mechanism for channel access in vehicular Ad Hoc networks

A file repair method for Multimedia Broadcast Multicast Service (MBMS) and a UMTS network are disclosed. According to the method, a data structure is established according to a repair request message sent from a user equipment. Each repair block is multicast to the user equipment that requested it by using the original MBMS Bearer Service for file downloading according to the data structure. The present invention does not need any extra traffic and additional control signaling to allow each user equipment to receive required repair blocks.

File repair method for MBMS and UMTS network

Growing community of inventors

Xindian, Taiwan

Yen-Cheng Lai