Telefonaktiebolaget Lm Ericsson (Publ)

Daniel Dufour

Vincent Guimont

Sylvain Briere

Ulises Olvera-Hernandez

Mohammed Sammour

Patrik Torgny Karlsson

Richard Joseph Brunner

Torbjorn Ward

Daniel Bringby

Kim Phuong Vo

Anders Sandell

Sylvain LaBont&eacute;

Anna Cecilia Brandstrom

Hangkan Olsson

Richard J Brunner

Radio environment statistics data useful in determining frequency plan revisions is collected in each one of a plurality of separate recording periods. Following conclusion of each recording period, a frequency plan revision algorithm is executed to process the collected radio environment statistics data and determine a frequency plan revision for implementation. The collected data that is considered by the algorithm includes not only that data which was collected in a current recording period, but also that data collected in previous recording period(s) thereto. More specifically, only the previous recording period data that is considered reliable is processed by the algorithm along with the current recording period data. Reliable data is identified as that data relating to a measurement made on frequency whose radio environment statistics have not been adversely affected by an implementation of a frequency plan revision in the meantime since making the measurement.

Consideration of historical MAHO measurements for frequency plan revision determinations

Utilizing a sequential local search optimization algorithm, a determination is made of the cell/transceiver retunes needed to implement, given a current frequency plan, a better frequency plan for a certain cellular communications system. Each of the individual cell/transceiver retunes is evaluated to determine if it meets certain save criteria, and if so, is saved as an intermediate frequency plan in a sequence of saved intermediate frequency plans necessary to migrate from the current frequency plan to the determined near-optimal frequency plan. A sequential implementation of these intermediate frequency plan revisions is then made to gradually reach, in a known and controlled manner, the better frequency plan.

Gradual frequency plan revision methodology

Interference and bit error rate measurements are made on the uplink and downlink to determine communications quality. Mobile station mobile assisted hand-off (MAHO) functionality is utilized to make the downlink measurements. Following filtering, the measurements are evaluated to identify potential candidates for reallocation. In one type of evaluation, when measured downlink bit error rate on a selected frequency is lower than a threshold and is worse than measured uplink bit error rate, then a better quality candidate is chosen to replace the selected frequency. In another type of evaluation, when a best available candidate has better interference than a worst quality one of the selected frequencies, that best candidate is chosen to replace the selected frequency.

Automated tool method for frequency plan revision within a cellular telephone system

A system and method of restricting an on-going call of a fixed subscriber to a fixed subscription area (FSA) in a cellular telecommunication system having a plurality of cells and a plurality of subscribers. The plurality of subscribers includes at least one fixed subscriber assigned to the FSA and engaged in an on-going call in a serving cell. The system and method detect when the fixed subscriber is crossing a cell border between the serving cell and a neighbor cell, determine whether the neighbor cell is located in the FSA, and drop the on-going call of the fixed subscriber upon determining that the neighbor cell is located outside the FSA.

System and method for restricting mobility of subscribers assigned to

A frequency plan revision proposal is evaluated to determine whether it is compatible with the current cell configuration by insuring that sufficient frequencies having appropriate operating modes are available for assignment to meet the traffic and control channel requirements and availability of the included cell transceivers. A record is kept of previously approved proposals resulting in a revision to the frequency plan assignment. A determination is then made as to whether the current proposal if implemented would have an adverse effect on the network in view of the previously approved proposals maintained by the record. An adverse effect is found when: a sub-frequency group/frequency dropped and/or added by the proposal at issue matches or is adjacent to a sub-frequency group/frequency dropped and/or added in the record of the previously approved proposals; and the distance between the cell of the proposal at issue and the cell of the previously approved proposal in the record are within a certain threshold distance of each other.

Method for frequency mode validation for, frequency assignment for, and

Utilizing a three pass processing procedure, a frequency plan revision proposal is defined, verified, implemented and confirmed by a network operator. In a first pass (evaluation), interference and bit error rate measurements are evaluated and used to create one or more proposals. These proposals are evaluated to confirm compatibility with the current cell configuration, coordination with previous proposals, and assignment of frequencies. In a second pass (pre-update verification), more measurements are evaluated to confirm the first pass proposals. A single proposal for each selected cell is then chosen for implementation in a network update. In a third pass (post-update verification), the measurements are again evaluated to verify, following the update, that the implementation of the proposal had a positive effect on the network.

Operator assisted tool and method for frequency plan revision within a

A neighborhood zone covering an enclosed or surrounded environment, such as a man-made building or high-rise, is defined within a mobile telecommunications network by associating a plurality of base stations with respective cell areas. A same neighborhood list indicating all measurement channels being utilized within the neighborhood zone by said plurality of base stations is then further defined. The defined same neighborhood list is then transmitted by each of the base stations within its respective coverage area. A mobile station traveling within the neighborhood zone then scans and reports measurements from the indicated measurement channels to the serving mobile telecommunications network. The mobile telecommunications network then effectuates a handover in accordance with the received signal measurements. An idle mobile station further utilizes the measurements to effectuate a cell re-selection.

Providing a neighborhood zone within a mobile telecommunications network

In a cellular network having a first cluster of base stations serving a first group of mobile stations over digital RF channels and a second cluster of base stations, collocated with said first cluster, for serving a second group of mobile stations over analog RF channels, wherein some of the base stations in the second cluster have cells which overlap with cells of the first cluster, a method is disclosed for setting up a call on an analog voice channel of a base station of the second cluster while a mobile station is being served on a digital control channel of a base station in the first cluster.

Call set-up on 800 MHz analog voice channel from 1900 MHZ digital

There is disclosed a system and method for accessing a cellular telecommunications network serving a plurality of normal subscribers and a plurality of fixed subscribers. The normal and fixed subscribers access the system through a plurality of cells and a plurality of base stations electronically connected to a mobile switching center (MSC). Each of the base stations transmits radio frequency signals over a coverage area defining one of the cells. The system differentiates during system access the normal subscriber from the fixed subscriber. The system permits the normal subscriber access to the system through any one of the plurality of cells. The system permits the fixed subscriber restricted call setup to the system through a fixed subscription area (FSA) defined for the fixed subscriber to include at least one of the cells. The system includes a redirection access function for redirecting access to the system by the fixed subscriber to one of the cells in the FSA when the fixed subscriber initially accesses the system through a serving cell excluded from the FSA. A fixed subscriber who travels near or slightly outside cell coverage area of the FSA is able to access the cellular system by redirecting the access to a cell defined as part of the subscriber's FSA.

System and method for restricting call setup to a fixed subscription

In a fixed cellular telephone system, an improved caller interface is provided wherein the taking of a standard wireline telephone set off-hook triggers the establishment of a voice path between the telephone set and the cellular system switch. A dial tone is then applied by the cellular system to the voice path and a caller enters the digits of the telephone number of the party to which the call is directed. The caller dialed digits are transmitted over the voice path to the cellular system switch where they are processed to complete the call connection to the called party. The dialed digits are further analyzed on a one-by-one basis to determine whether improper or unauthorized digits or combinations of digits have been entered by the caller. The caller interface provided by the fixed cellular system of the present invention accordingly operates in a substantially identical manner to that experienced with a conventional wire-based telephone system and in an improved manner over that provided in a conventional cellular system.

Method and apparatus for providing an improved caller interface in a

A mobile terminal locator for locating a mobile terminal in a cellular telecommunication system having a plurality of base stations and associated cells. The mobile terminal locator identifies a plurality of candidate handoff cells having sufficient signal strength to maintain a call with the mobile terminal, and forces sequential handoffs of the mobile terminal from its serving cell to the plurality of candidate handoff cells. The locator then measures signal strength and propagation delay between the mobile terminal and each base station associated with each of the plurality of candidate handoff cells and between the mobile terminal and the serving base station. Either the signal strength, the propagation delay, or both are then used to calculate a distance between the mobile terminal and each base station associated with each of the plurality of candidate handoff cells and between the mobile terminal and its serving base station. From the calculated distances, a plurality of arcs of possible locations of said mobile terminal are then defined, the arcs being centered on the serving base station and each base station associated with each of the plurality of candidate handoff cells. Finally, the mobile terminal locator calculates an intersection point of the plurality of arcs of possible locations, the intersection point defining the location of the mobile station. The locator may operate in cellular telecommunication systems with or without synchronized timing reference signals from the base stations.

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Blainville, Canada

Daniel Dufour