WO2001045442A1 - Procede et appareil pour determiner les zones de chevauchement dans un systeme de communication cellulaire - Google Patents

Procede et appareil pour determiner les zones de chevauchement dans un systeme de communication cellulaire Download PDF

Info

Publication number
WO2001045442A1
WO2001045442A1 PCT/EP2000/011362 EP0011362W WO0145442A1 WO 2001045442 A1 WO2001045442 A1 WO 2001045442A1 EP 0011362 W EP0011362 W EP 0011362W WO 0145442 A1 WO0145442 A1 WO 0145442A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
mobile device
base station
response
coverage overlap
Prior art date
Application number
PCT/EP2000/011362
Other languages
English (en)
Inventor
Howard John Thomas
Thomas Michael Quirke
Original Assignee
Motorola Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Limited filed Critical Motorola Limited
Priority to AU17018/01A priority Critical patent/AU1701801A/en
Publication of WO2001045442A1 publication Critical patent/WO2001045442A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/18—Network planning tools
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/32—Hierarchical cell structures

Definitions

  • This invention relates to a cellular telecommunication system and a method of management of a cellular telecommunication system and is relevant to a method of automatic frequency reuse.
  • the invention is particularly, but not exclusively, applicable to a method and apparatus for determining the coverage overlap between two neighbouring base stations, thereby enabling frequency reuse to be automatically determined.
  • the invention is also applicable to a method and apparatus for assisting handover in a cellular telecommunication system.
  • AFA Automatic frequency allocation
  • a capsule cellular system a plurality of adjacent serviceable cells are assigned traffic channel carriers according to a regimented (or sequenced) frequency re-use pattern but dedicated individual control channel carriers do not exist for individual cells.
  • a single broadcast control channel overlays a multitude of pico-cellular type traffic channels, with individual pico-cellular base station heads operating in a simulcast mode to transmit the BCCH control information.
  • a single wide-area BCCH services a plurality of cellular capsules, with the BCCH transmitted in the down-link from, effectively, a global base station.
  • This form of system design is relatively easy to implement, especially in an indoor environment, and is not wasteful of frequency resources that would otherwise be required in the provision of individual BCCHs in individual cells according to a BCCH frequency re-use pattern.
  • the system as a whole is unable to benefit from being able to continuously monitor down-link transmissions, since there is a singular BCCH transmission across the cellular service area.
  • non- continuous down link transmissions are advantageous since the environment supports a higher (i.e. better) carrier to interference (C/l) ratio.
  • C/l carrier to interference
  • the system is generally better able to support data transfer, such as required in the Group Packet Radio System (GPRS).
  • GPRS Group Packet Radio System
  • it is preferably to have a good C/l since this reduces the requirement for overhead associated with forward error correction coding and hence results in a system that has a corresponding increase in data traffic throughput.
  • Data collection during AFA usually relies upon the up-link signal strength measurements made on the traffic received by a number of neighbouring base stations. This may be augmented by regular down-link measurements, made by a mobile station within a particular cell and reported by the mobile station on one of the associated control channels, such as the SACCH.
  • these measurements are of limited use for a variety of reasons; for clarity, the following discussion has been limited to the particular problems experienced in a traditional GSM cellular system.
  • the down-link measurements are only made by the mobile station on signals from base stations of adjacent cells. Measurements on signals from the next ring of cells, i.e. one cell removed from the adjacent cells, are also important for determining the best reuse pattern.
  • the base station identity code (BSIC) from each of these cells is, as a consequence, decoded as part of the measurement process. Any problem frequencies used by the neighbouring base stations which result in the BSIC being corrupted will not be reported.
  • BSIC base station identity code
  • a method of determining coverage overlap in a cellular wireless telecommunications system including a plurality of base stations each serving a radio cell and at least one mobile device adapted to communicate with the base stations, comprising:
  • the method may comprise recording information regarding the presence or absence of a response from the mobile device and the location of the mobile device and using the recorded information to produce a map of coverage overlap in one or more radio cells.
  • the first signal and/or second signals may be paging messages transmitted on a paging channel.
  • the first and/or second signals may include a location update message.
  • the second signal may, in the alternative, be a dummy burst on the same frequency as the first signal message.
  • the power of the second signal is a programmable value and steps (a) to (c) may be repeated using a second signal of differing powers.
  • the compatibility relationship (or coverage overlap) between two base stations may be measured for some or all of the channels defined by the telecommunications protocol, and thus employed by the base stations. Where those channels function in practice on different frequencies, each frequency may be mapped in each cell for coverage overlap.
  • a cellular wireless telecommunications system for determining coverage overlap comprising: a first base station; a second base station; at least one mobile device said first base station including a first transmitter for transmitting a first signal to the mobile device, said second base station including a second transmitter for transmitting a second signal capable of interfering with said first signal; said at least one mobile device including means for receiving said first signal, means for decoding said first signal and means for transmitting in response to said decoded first signal a reply signal; said system including means for recording from the presence or absence of a reply signal from the mobile device whether the mobile device has successfully received the first signal.
  • the system may comprise mapping means for determining a map of the coverage overlap between the first and second signals after repeated transmission of said first signal and said second signal.
  • the system may also comprise means for recording information regarding the presence or absence of a response from the mobile device and the location of the mobile device
  • On advantage of the invention is that mobile devices other than those carrying traffic, i.e. engaged in communication, may be used to contribute to the measurement campaign.
  • the number of mobile devices reporting during the test sequence may be dramatically increased leading to a much faster mapping.
  • the period required to re-plan frequency reuse in a group of cells may thus be considerable reduced, leading to a much faster response.
  • Another advantage is that the method may be applied equally well to macro-, micro- and pico-cell systems and to a capsule cellular system. No additional equipment is needed to implement the testing process and thus the process may be implemented using, for example, a software upgrade to the existing BTS and BSC software.
  • Yet another advantage is that measurements on signals from base stations other than those on the neighbour lists can be made, increasing the flexibility of the system considerably.
  • Still another advantage is the problematic frequencies can be rapidly and easily identified during the testing procedures, thereby enabling such frequencies to be eliminated from any frequency re-plan.
  • Still another advantage is that faster handover may be achieved since the need for the mobile devices to decode and re-decode the base station identity code (BSIC) is eliminated.
  • BSIC base station identity code
  • Figure 1 shows a cellular layout of a mobile cellular communications system
  • Figure 2 shows in outline a capsule mobile cellular communications system.
  • FIG. 1 shows in outline a mobile cellular communications system employing a GSM communications protocol.
  • An end-user device (mobile station 10) is in communication with its nearest base transceiver station (BTS 11 ) across an air interface.
  • the BTS is connected to the rest of the telephone network (15) via a base station controller (BSC 12) and mobile switching centre (MSC 13).
  • BSC 12 base station controller
  • MSC 13 mobile switching centre
  • Each BTS serves one cell and may contain one or more transceivers.
  • Each BSC may control one or more BTS; a micro-cellular environment may contain a number of micro cells that are all controlled by a single BSC.
  • Each MSC may also be connected to one or more BTSs and may also be connected to an operations and management centre (OMC 14).
  • Each OMC may manage an entire network or sections of a larger network. For convenience, only those base transceiver stations in communication with the mobile are illustrated in figure 1 ; the remaining cells will all have a serving base transceiver station
  • MS 10 is in the coverage area, or cell (16), of BTS 1 1.
  • Adjacent BTS 17 has a coverage area, or cell 18. Both BTSs are shown as controlled by a single BSC, for convenience, but the BTSs may be controlled by two, independent BSCs which form part of the telecommunications network.
  • BTS 11 Under the direction of MSC 13, BTS 11 transmits a first signal, containing a first message, to MS 10.
  • the MSC instructs BTS 17 to transmit a second interfering signal containing a second message, timed to coincide and conflict with the first signal.
  • the controller is able to determine where in each cell the signals from each BTS overlap, or conflict, and where the signals are received in more or less isolation.
  • the mobile cellular communications network employs a conventional GSM implementation
  • the following description illustrates how the network may be mapped for BCCH carrier frequency compatibility (or coverage overlap).
  • BTS 17 re-tunes traffic timeslot 0 to the BCCH carrier frequency of BTS 11. Both BTSs, under the direction of MSC13, page MS 10 using the same carrier frequency. Whether MS 10 acknowledges either page or not is recorded, along with information regarding the MS location, for subsequent statistical analysis, either by a local network element such as MSC 13 or by a centralised network element such as OMC 14. If MS 10 responds to either page, the response is unconditionally ignored and the otherwise normal transaction is aborted. The process may be repeated over time, especially if MS 10 is moving, or with another different, non-serving BTS.
  • the interfering signal may be broadcast using another channel, such as the paging channel (PCH), which reduces the impact on the paging capacity of both the first and second base stations
  • PCH paging channel
  • the frequency compatibility (or coverage overlap) of other channels may also be mapped using the above method.
  • the interfering signal may be broadcast using another channel or frequency for full AFA mapping.
  • the above method may be used to fault find, when cells are experiencing conflict difficulties, or as a pre-emptive test of any frequency re- plan.
  • the above methods have been described using a single mobile station, for clarity. However, the system functions equally well when a number of mobile stations are all signalled.
  • the pre-emptive testing in particular, may be scheduled for periods when the cells experience low traffic rates, e.g. during off-peak times.
  • the mobile cellular communications network employs a capsule GSM implementation
  • the following description illustrates how the network may be mapped for BCCH carrier frequency compatibility and coverage overlap (or conflict). This information may be used to assist handover.
  • FIG. 2 shows in outline a capsule mobile cellular communications system 20 according to the invention.
  • Each base station (21 a - 21 f) broadcasts to a capsule cell (22a - 22f) and comprises two transceiver systems.
  • One transceiver is dedicated to transmitting the BCCH at a frequency identical to that of the other base stations to provide a simulcast BCCH.
  • the second transceiver carries traffic channels, at unique or quasi-unique (that is, if co- channel interference remains at acceptably low limits) frequencies.
  • Each base station is connected to a central controller (BTS 23) which controls, amongst other things, timing synchronisation.
  • Mobile stations (24) are free to move around within the system.
  • the capsule concept thus enables frequency reuse and supports uneven traffic effectively by creating a single large overlay cell with simulcast broadcast throughout the area, within which numerous capsule cells exist.
  • a mobile station is likely to remain within this large overlay cell during the period of the call, very few inter-overlay cell handovers are required and, consequently, the majority of handovers will be of the intra-overlay (or inter- capsule) cellular type. Since there is effectively a single BCCH, the mobile cannot identify target capsule cells, i.e. the handover process is not mobile assisted. Instead the capsule cells identify the target mobile stations by making measurements of the strength of neighbouring up-link traffic.
  • the known handover method requires the base station for each capsule cell to measure a neighbour capsule cell's traffic signal strength for the intra capsule neighbour list.
  • the information on which timeslots are active is available at the common controller. Measurement is achieved by retuning the BCCH transceiver to receive signals broadcast at the traffic carrier frequency of the neighbouring capsule cell in question. The timeslot preceding and succeeding the retuning will be lost due to retuning time. (Note that the capsule cells are inherently synchronised).
  • the number of opportunities for measurement per slow associated control channel (SACCH), if dynamically calculated, is based on the number of current active mobile stations in the surrounding cells and the tolerated number of deletions of the RACH for timeslot 0, 1 and 7 due to retune time.
  • the number of measurement opportunities will be the number of tolerable deletions divided by the number of intra capsule neighbours. These measurements are then averaged over a SACCH period and on a mobile by mobile basis a neighbour list is formed by collating up-link measurements taken by neighbouring base stations. The up-link measurements are converted into down-link equivalent measurements termed 'pseudo down-link measurements'. This is achieved by accessing the current MS transmit power stored at the common controller. One mechanism used is to rank the strongest six adjacent cell list. Thus the best six neighbours can include a mix of normal and capsule cells. Note than a special capsule cell id tag is required to index capsule cells. This information is passed to the handover code via the measurement report in the normal manner. The measurement report is thus intercepted and modified before reaching the handover code.
  • the handover code is presented with a seemingly normal measurement report the handover triggers can operate as normal.
  • a handover is identified a further clarification regarding the nature of the target is required. That is, it needs to be known if the target cell is normal or capsule and this is achieved by reading the id tag. If the target is a capsule cell then handover of a targeted intracellular type is performed. If the target cell is non-capsule then a standard intercellular handover is performed.
  • BTS 21 a under the direction of BTS 23, pages MS 24 using the simulcast BCCH carrier frequency.
  • BTS 21 b transmits an interfering signal.
  • whether MS 24 acknowledges either page or not is recorded by the BTS 23 for subsequent statistical analysis. If MS 24 responds to the page, the response is unconditionally ignored and the otherwise normal transaction is aborted.
  • the process may be repeated with another different, non-serving neighbouring BTS, such as 21 c.
  • the interfering signal may be broadcast using another channel, such as the paging channel which reduces the impact on the paging capacity of the system, or another frequency.
  • the BTS may use this information to determine whether handover is appropriate.
  • the neighbour measurements can include a mix of normal and capsule cells.
  • a special capsule cell id tag is required to index capsule cells, also as above, this information is passed to the handover code via the measurement report in the normal manner and the measurement report is intercepted and modified before reaching the handover code.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention porte sur un procédé de détermination de zone de chevauchement dans un système de télécommunication sans fil cellulaire et sur un système de télécommunication sans fil cellulaire comportant des stations de base et des dispositifs mobiles, pour la détermination de zone de chevauchement. Un premier signal est transmis d'une première station de base à un dispositif mobile. Si le signal est reçu avec succès, le dispositif mobile transmet une réponse. Un second signal pouvant interférer avec ledit premier signal est transmis depuis une seconde station de base. Par l'enregistrement, en fonction de la présence ou de l'absence d'une réponse du dispositif mobile, de la réception réussie du premier signal par le dispositif mobile, et par la répétition de la transmission des premier et second signaux comme requis, la zone de chevauchement entre les premier et second signaux peut être déterminée.
PCT/EP2000/011362 1999-12-18 2000-11-13 Procede et appareil pour determiner les zones de chevauchement dans un systeme de communication cellulaire WO2001045442A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU17018/01A AU1701801A (en) 1999-12-18 2000-11-13 Method and apparatus for determining coverage overlaps in a cellular communication system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9929858.0 1999-12-18
GBGB9929858.0A GB9929858D0 (en) 1999-12-18 1999-12-18 Method and apparatus for determining coverage overlaps in a cellular communication system

Publications (1)

Publication Number Publication Date
WO2001045442A1 true WO2001045442A1 (fr) 2001-06-21

Family

ID=10866515

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2000/011362 WO2001045442A1 (fr) 1999-12-18 2000-11-13 Procede et appareil pour determiner les zones de chevauchement dans un systeme de communication cellulaire

Country Status (3)

Country Link
AU (1) AU1701801A (fr)
GB (1) GB9929858D0 (fr)
WO (1) WO2001045442A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2399990A (en) * 2003-03-28 2004-09-29 Motorola Inc Method for determining a coverage area overlap in a cell based communication system
WO2012155666A1 (fr) * 2011-09-19 2012-11-22 中兴通讯股份有限公司 Procédé, dispositif et système pour acquérir le taux de couverture d'une cellule voisine ainsi qu'une relation de couverture
US11622307B2 (en) * 2017-07-21 2023-04-04 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Wireless communication system and method for handling wireless communication enhancing handover

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2236456A (en) * 1989-09-29 1991-04-03 Televerket Method for determining that pairs of cells in a mobile radio system are completely measured
US5878328A (en) * 1995-12-21 1999-03-02 At&T Wireless Services, Inc. Method and apparatus for wireless communication system organization

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2236456A (en) * 1989-09-29 1991-04-03 Televerket Method for determining that pairs of cells in a mobile radio system are completely measured
US5878328A (en) * 1995-12-21 1999-03-02 At&T Wireless Services, Inc. Method and apparatus for wireless communication system organization

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2399990A (en) * 2003-03-28 2004-09-29 Motorola Inc Method for determining a coverage area overlap in a cell based communication system
GB2399990B (en) * 2003-03-28 2005-10-26 Motorola Inc Method for determining a coverage area in a cell-based communication system
WO2012155666A1 (fr) * 2011-09-19 2012-11-22 中兴通讯股份有限公司 Procédé, dispositif et système pour acquérir le taux de couverture d'une cellule voisine ainsi qu'une relation de couverture
US11622307B2 (en) * 2017-07-21 2023-04-04 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Wireless communication system and method for handling wireless communication enhancing handover

Also Published As

Publication number Publication date
AU1701801A (en) 2001-06-25
GB9929858D0 (en) 2000-02-09

Similar Documents

Publication Publication Date Title
EP0626122B1 (fr) Procede de mesure de stations de base adjacentes dans un systeme de radiocommunications amrt et systeme de radiocommunications amrt
EP0882380B1 (fr) Procede et systeme de mesure de signaux dans un systeme de telecommunications a fonction de transfert assistee par la station mobile (maho)
RU2237363C2 (ru) Способ и устройство для переключения ячеек
JP3252911B2 (ja) 時分割多元接続無線システム、セル内容量割当て方法、及びセル内ハンドオーバを実行する方法
US5839070A (en) System and method for hyperband cell interoperability in a cellular telecommunications network
US5901145A (en) Mobile station handoff between a spread spectrum communications system and a frequency division communications system
US20070161374A1 (en) Co-channel handover in a cellular network
JP2000515347A (ja) 周波数変換型中継器を使用する時分割セルラーシステムのセル拡張
EP2036375A1 (fr) Procede et agencement pour un transfer intercellullaire dans un reseau d'acces radio
CN103329593A (zh) 相邻小区信号强度的速报
US7701899B2 (en) Base station identification
EP2172034A1 (fr) Procédé de diffusion d'informations systèmes dans des cellules de communication pour un transfert
US6002678A (en) Method of handing-off a remote unit based on overhead information start times
AU724819B2 (en) A method to arrange monitoring of base stations with discontinuous control channel transmissions
USRE40984E1 (en) Reporting communication link information
WO2001045442A1 (fr) Procede et appareil pour determiner les zones de chevauchement dans un systeme de communication cellulaire
EP0824842B1 (fr) Acheminement de donnees de remplissage a des emetteurs dans une station radio de base d'un systeme de radiocommunication
EP1086603B1 (fr) Reseau de telecommunication mobile et son procede de fonctionnement
WO1999011084A1 (fr) Dispositif et procede pour la transmission de donnees
KR20100073603A (ko) 이동성 네트워크 시스템에서 프리엠블 변경 방법 및 이를 위한 시스템
JPH1118134A (ja) デジタルセルラ無線通信システムの基地局から同報制御論理チャンネルを送信する方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase