eprintid: 69
rev_number: 4
eprint_status: archive
userid: 4
dir: disk0/00/00/00/69
datestamp: 2006-06-19
lastmod: 2015-05-29 19:46:41
status_changed: 2009-04-08 16:53:30
type: report
metadata_visibility: show
item_issues_count: 0
creators_name: Billingham, John
creators_name: Leese, Robert
creators_name: Rajaniemi, Hannu
contributors_name: Gould, Tim
contributors_name: Halliday, Sam
contributors_name: Please, Colin
contributors_name: Pu, Ida
contributors_name: Wilson, Eddie
contributors_name: Winterstein, Daniel
title: Frequency reassignment in cellular phone networks
ispublished: pub
subjects: telecom
studygroups: esgi53
companyname: Motorola
full_text_status: public
abstract: In cellular communications networks, cells use beacon frequencies to ensure the smooth operation of the network, for example in handling call handovers from one cell to another. These frequencies are assigned according to a frequency  plan, which is updated from time to time, in response to evolving network requirements. The migration from one frequency plan to a new one proceeds in stages, governed by the network's base station controllers. Existing methods result in periods of reduced network availability or performance during the reassgnment process.

The problem posed to the Study Group was to develop a dynamic reassignment algorithm for implementing a new frequency plan so that there is little or no disruption of the network's performance during the transition. This problem was  naturally formulated in terms of graph colouring and an effective algorithm was developed based on a straightforward approach of search and random colouring.
problem_statement: In cellular communications networks, cells use beacon frequencies to ensure the smooth operation of the network, for example in handling call handovers from one cell to another. These frequencies are assigned according to a frequency plan, which is updated from time to time, in response to evolving network requirements. The migration from one frequency plan to a new one proceeds in stages, governed by the network’s base station controllers. Existing methods result in periods of reduced network availability or performance during the reassignment process. The Study Group was asked to develop an algorithm for implementing a new frequency plan that maintains service quality during the transition.
date: 2006
date_type: published
pages: 32
citation:   Billingham, John and Leese, Robert and Rajaniemi, Hannu  (2006) Frequency reassignment in cellular phone networks.  [Study Group Report]     
document_url: http://miis.maths.ox.ac.uk/miis/69/1/Motorola-report.pdf