應用於蜂巢式行動通訊系統之競爭性WIMA/SAD協定性能分析

Performance Analysis of a Contention-Based WIMA/SAD Protocol for the Cellular Mobile Communications

高誌陽(Chih-Yang Kao)

指導教授 ： 馬杰

元智大學/工程學院/電機與資訊工程研究所/碩士(1997年)

摘要

本篇論文主要研究方向為整合語音與數據之蜂巢式行動通訊網路頻
道接技術，在論文中提出一種具有語音偵測器功能之無線整合多重接
取(Wireless Integrated Multiple Access with Speech Activity
Detector, WIMA/SAD)協定。語音資料利用時槽式ALOHA(slotted ALOHA)
的方式包封競爭預約時槽(access slot)中的位子，當競爭訂位成功後
，才有權力使用時槽通話；而數據資料則採用先到先服務的方式包封預
約時槽，若無空閒時槽則放置在暫存區等待傳輸。一階三維馬可夫鏈
被作為競爭性WIMA/SAD的模型，進行WIMA/SAD協定在分時雙工(TDD)和
分頻雙工(FDD)系統的性能分析。DCS-1800的系統參考數據被用來計算
競爭性WIMA、移動邊界WIMA以及WIMA/SAD之語音阻隔機率(voice
blocking probability)及平均資料包封傳輸延遲(expected
data-packet delay)。
分析結果顯示語音通話使用競爭方式爭取通話權時，語音完成機率
越高以及語音到達機率愈小時，語音阻隔機率就會越低，並且當行動台
數增加時，其語音阻隔機率則會越高；競爭性WIMA/SAD協定的資料傳輸
延遲的表現較競爭性WIMA協定好，資料包封傳輸延遲會隨行動台數資料
到達率增加及語音完成率減少而增加。競爭性WIMA/SAD協定對於競爭性
WIMA協定來說可以有較高且較穩定的傳輸成功率。

關鍵字

多重接取 ； 通訊協定 ； 整合式 ； 競爭性

並列摘要

In this paper, the channel access protocol of the cellular
mobile network to integrate the voice-call and data are
investigated. A contention based Wireless Integrated Multiple
Access with Speech Activity Detector (WIMA/SAD) protocol is
proposed. A voice calls of a mobile station contend for the
access slot to share the network resource as in slotted
ALOHA system. The data packet can tolerate longer delay so
that the first-come-first-in algorithm is used for a data
packet to reserve the access slot. If there is no time slot
available for the voice calls or data packet in the access
slots, voice calls are blocked and data packets are stored in
the memory and waiting for the transmission. The performance
of the contention based WIMA/SAD protocols for Time Division
Duplex (TDD) and Fre-quency Division Duplex (FDD) systems are
evaluated. The contention based WIMA/SAD protocol is modeled
by a three-dimensional first-order Makov chain. The blocking
probability of voice calls and the expected data packet delays
for contention based fixed-boundary WIMA, contention based
movable-boundary WIMA, and contention based WIMA/SAD protocols
are evaluated and compared by using the specifications of
DCS-1800.
The analytical results show that the voice call blocking
prob-ability of contention based WIMA protocols is decreased
with the increasing voice completion rate and voice call
arrival rate. The ex-pected data packet delay of contention
based WIMA/SAD protocol is less than that of contention based
WIMA protocol. The expected data packet delay of contention
based WIMA/SAD is increased with the increasing number of
mobile stations, data arrival rate and decreasing voice
completion rate. The contention based WIMA/SAD proto-col can
provide higher and move stable data throughput that contention
based WIMA protocol.

並列關鍵字

multiple access ； protocol ； integrated ； contention-based

參考文獻

Analysis of Integrated Voice/Data Multiplexers With and Without Speed

Activity Detectors," IEEE Journal on Select. Areas in Comm., vol. SAC-1,

Data Transmission System Using Packet Reservation Multiple Access," IEEE

Trans. on Veh. Technol., vol. 43, No.2, May 1994.

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