Browse Prior Art Database

Optimized Site Association and Call Initiation in a Wideband Data System

IP.com Disclosure Number: IPCOM000007150D
Original Publication Date: 2002-Feb-27
Included in the Prior Art Database: 2002-Feb-27
Document File: 2 page(s) / 70K

Publishing Venue

Motorola

Related People

Bob LoGalbo: AUTHOR [+4]

Abstract

Many data systems (TETRA, Project 25, GPRS) have a dedicated logical control channel or control frequency. In order for a Mobile Station to initiate a call, it must first request, via the control channel or control frequency, a dedicated channel or frequency to place the call: this incurs latency for call initiation. This also dedicates an entire channel or frequency for control which could otherwise be utilized for user plane information. The following proposal presents a method of associating to a site without a dedicated control channel.

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Optimized Site Association and Call Initiation in a Wideband Data System

 

By Bob LoGalbo, Greg Dertz, Alan Conrad and Darrell Stogner
 
 

Many data systems (TETRA, Project 25, GPRS) have a dedicated logical control channel or control frequency.  In order for a Mobile Station to initiate a call, it must first request, via the control channel or control frequency, a dedicated channel or frequency to place the call:  this incurs latency for call initiation.   This also dedicates an entire channel or frequency for control which could otherwise be utilized for user plane information.   The following proposal presents a method of associating to a site without a dedicated control channel.

Assume a wideband system (network) will consist of some number of sites and at least one core server located centrally of all of the sites.

A site will consist of (at a minimum):

·         1 High-speed Site Controller (HSC)

·         1 Home Frequency Base Station

·         1+N Traffic Frequency Base Stations (The Base Stations can be of any  combination of bandwidths at a site)

Figure 1 – High Speed Data Site Architecture

There will be one Home Frequency pair per site (pair being a rx and tx frequency).   If a site consists of only one frequency pair, it will be the Home Frequency pair.  If there is more than one Base Station (BS) per site, one BS will be assigned as the Home Frequency BS and the others will be the primary Traffic frequencies.  All inbound frequencies of all BS’s at a site bear user plane traffic. The outbound frequencies of all of the BS’s bear user plane traffic but the Home Frequency Base Station broadcasts other site specific information as well.  None of the frequencies have a dedicated control slot, inbound or outbound (e.g. every 4th or 8th TDM slot);  any outbound or inbound slot has the potential to carry control.

The purpose of the Home Frequency is to be the initial point of access for a Mobile Station (MS) that has not associated to the site.  This is the frequency that an MS will seek if it is not associated to the site or registered to the system.  This frequency will broadcast all information necessary to establish Layer 2 services at the site.  Because each site will have a Home Frequency, and  because this will be the point of access for an MS to a site, the neighbor site (i.e. cell) lists consist of a list of adjacent site Home Frequencies. 

Each Home Frequency will broadcast a list of that given site’s Traffic Frequencies with the  frequencies’ characteristics (e.g. available throughput) .  The MS will listen and scan the Home Frequencies of adjacent sites.  It will get the list of Traffic Frequencies associated with a given site and scan those Traffic Frequencies evaluating signal quality.  In the invention’s simplest implementation, the MS will choose the Traffic Frequency with the appropriate available throughput and the best signal quality as the frequency onto which it will first access the site and then camp.

Upon accessing the site over this chosen Traffic Frequency, it wi...