Researches On A Wireless Packet Access System For Integrated Services

To satisfy the needs for supporting integrated services such as video, data and voice etc in special applications, the paper proposes a private packet wireless access network for integrated services. A feasible MAC protocol is discussed, and the demo system hardware is designed and implemented.Firstly, it briefly introduces the research backgroud and the target, brings up the whole architecture, designed the concret scheme.Secondly, the system physical layer's key technology—Direct Sequence Spread Spectrum (DSSS) is described. After the study on the spread spectrum basic theory and the DSSS system, the reasons for adopting DSSS are presented.Then, the MAC protocol is studied. From the primal ALOHA protocol, it introduces and analyses several popular MAC protocols such as Slot ALOHA, CSMA. WLAN's IEEE 802.11b MAC protocol is given extra attention to. At the end, the dedicated MAC protocol which is based on the characteristic of the system is described.Finally, the hardware design and implementation of the handset and basestation (Access Point) are thorough discussed. It porvides detailed hardware block digrams of handset and AP. Also, the core processor Triscend E5 and its development flowcharts are introduced. Likewise, other chips and its design outline are intorduced. The interface designs are illustrated separately. The process to implement PCB form and the principles to be abided in the design of PCB are provided. The debugging plan of hardware is concisely shown.