公开(公告)号：EP0506688A4

公开(公告)日：1996-07-17

申请号：EP91900097

申请日：1990-12-03

Applicant: MOTOROLA INC

Inventor： FREEBURG THOMAS A ,  KACZMARCZYK JOHN M ,  BUCHHOLZ DALE R ,  WHITE RICHARD E ,  CHANG HUNGKUN J ,  NOLAN MICHAEL P

IPC: H04L12/54 ,  H04J3/24 ,  H04Q7/00 ,  H04Q11/04

CPC classification number: H04L12/56

Abstract: In this invention a hierarchical addressing technique is employed in a packet communications system to enhance flexibility in handling packet information. This method permits packet message data (Fig. 3) and certain packet control data (Fig. 3) to be stored in memory locations (32, 34) without having to be duplicated at a different memory location prior to transmission of the packet. This method is preferably employed in a ring configuration in which a series of packets have addressing mechanisms which points sequentially to each other to form a ring of packets.

公开(公告)号：EP0567459A4

公开(公告)日：1994-08-24

申请号：EP91919540

申请日：1991-10-16

Applicant: MOTOROLA INC

Inventor： CHANG HUNGKUN J ,  DOSS WILLIAM KEVIN ,  NOLAN MICHAEL P ,  BUCCHOLZ DALE R ,  FREEBURG THOMAS A ,  MCKOWN JOHN ,  WHITE RICHARD E

IPC: H04B1/18 ,  H04B7/00 ,  H04B7/08 ,  H04B7/26 ,  H04W16/24 ,  H04W72/08

CPC classification number: H04W72/085 ,  H04B7/088 ,  H04W16/24 ,  H04W72/02

Abstract: An antenna selection technique is used in an RF communication system in which user modules (UM1-UM5) communicate with at least one node (N1-N2). The UM's (UM1-UM5) and nodes (N1, N2) each have multiple antennae. The combination of each UM and node antenna is evaluated at the UM. Based on at least signal quality, the UM (UM1-UM5) selects its antenna and the best node antenna for use. An alternate antenna is selected if a person is determined to be present in a predetermined area adjacent a UM (UM1-UM5) corresponding to a predetermined RF power level.