公开(公告)号：US20010033579A1

公开(公告)日：2001-10-25

申请号：US09792410

申请日：2001-02-23

Applicant: Tantivy Communications, Inc.

Inventor： George R. Nelson JR. ,  James A. Proctor JR. ,  John E. Hoffmann ,  Antoine J. Rouphael

IPC: H04L012/413

CPC classification number: H04W52/242 ,  H04L1/1607 ,  H04L12/5602 ,  H04L47/14 ,  H04L47/26 ,  H04L2001/0093 ,  H04W24/00 ,  H04W52/228 ,  H04W52/48 ,  H04W52/50 ,  H04W74/0825 ,  H04W74/0858

Abstract: In an illustrative embodiment of the present invention, a first channel is allocated for transmitting sporadically generated messages from multiple field units to a base station. The first channel is preferably divided into time slots in which a field unit transmits an access request message to the base station for establishing a communication link. In response to an access request message, feedback information is provided from the base station to multiple field units indicating whether a collision was detected on the first channel for a message transmitted in a previous time slot. In an instance when a collision is detected, the field unit will re-transmit an access request message at a previous power level setting based on a random back off time. If no collision is detected and the base station fails to transmit an acknowledgment message from the base station to the access requesting field unit, the power output level of the field unit is increased for successive message transmissions until the message is received.

Abstract translation: 在本发明的说明性实施例中，分配第一信道用于将来自多个场单元的偶发生成的消息发送到基站。 第一信道优选地被划分为时隙，其中，场单元向基站发送接入请求消息以建立通信链路。 响应于访问请求消息，反馈信息从基站提供给多个字段单元，指示在第一信道上是否检测到在先前时隙中发送的消息的冲突。 在检测到冲突的情况下，场单元将基于随机退避时间在先前功率电平设置下重新发送接入请求消息。 如果没有检测到冲突，并且基站无法从基站向接入请求字段单元发送确认消息，则对于连续的消息传输增加了现场单元的功率输出电平，直到接收到消息。