Browse Prior Art Database

Improvement of seamless handover reliability by a system page

IP.com Disclosure Number: IPCOM000010354D
Original Publication Date: 2002-Nov-21
Included in the Prior Art Database: 2002-Nov-21
Document File: 3 page(s) / 40K

Publishing Venue

Motorola

Related People

Mark Goldstein: ATTORNEY [+4]

Abstract

Asymmetry between uplink and downlink can cause the cell with acceptable signal strence on the downlink be bad for the uplink. This may cause dropping of the call and temporary break of radio link in TETRA-style system. It is proposed to use system paging to estimate both downlink and uplink quality of the target cell before continuing the call on the selected cell.

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Improvement of seamless handover reliability by a system page

Mark Shahaf

Nimrod Glazer

Rafy Carmon

Mark Goldstein

ABSTRACT

Asymmetry between uplink and downlink can cause the cell with acceptable signal strence on the downlink be bad for the uplink. This may cause dropping of the call and temporary break of radio link in TETRA-style system. It is proposed to use system paging to estimate both downlink and uplink quality of the target cell before continuing the call on the selected cell.

THE PROBLEM TO BE SOLVED

Modern systems of mobile communications use 2 different methods of changing serving cells during the call. In the first it is infrastructure (system) which makes a decision and controls the transition of mobile station (MS) from cell to cell (hands it over to the new cell). This is usual for cellular telephony and GSM. In the second method MS makes the decision about transition and system plays rather passive role. This method is used in some Dispatch Systems where group call is the prevailing mode of operation. It was also adopted by the TETRA Standard. One of the problems with this method is that MS makes its decision based on measurements of serving and neighbour cells transmission, that is on the quality of the downlink radio path. In practice, there can be some asymmetry between up- and downlink. This means that though downlink from the cell MS selects for transition is satisfactory, uplink quality can be insufficient for a proper operation.

PROPOSED SOLUTION

Th...