WO1994003993A1 - Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux - Google Patents

Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux Download PDF

Info

Publication number
WO1994003993A1
WO1994003993A1 PCT/US1993/006226 US9306226W WO9403993A1 WO 1994003993 A1 WO1994003993 A1 WO 1994003993A1 US 9306226 W US9306226 W US 9306226W WO 9403993 A1 WO9403993 A1 WO 9403993A1
Authority
WO
WIPO (PCT)
Prior art keywords
communication
network
wireless
communication resource
subscriber
Prior art date
Application number
PCT/US1993/006226
Other languages
English (en)
Inventor
Kenneth A. Felix
Morton Stern
Original Assignee
Motorola Inc.
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 Inc. filed Critical Motorola Inc.
Priority to JP6505300A priority Critical patent/JPH07504555A/ja
Priority to EP93916873A priority patent/EP0614589A4/fr
Priority to BR9305595A priority patent/BR9305595A/pt
Publication of WO1994003993A1 publication Critical patent/WO1994003993A1/fr
Priority to FI941503A priority patent/FI941503A0/fi

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/50—Allocation or scheduling criteria for wireless resources
    • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
    • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/16—WPBX [Wireless Private Branch Exchange]

Definitions

  • the invention relates to communication systems and, in specific, to wireless communication systems used in conjunction with private branch exchange communication systems.
  • PBXs Private branch exchange communication systems
  • PBXs are commonly used where a discrete group of people (e.g., employees of a company) need to communicate, in large measure, within the group.
  • a PBX, in providing service within the group, is typically limited to a fixed geographic area coincident with a company facility or group of facilities.
  • PBXs offer advantages in that calls between members of the discrete group are handled locally within the PBX and do not involve an associated public switch telephone network (PSTN). Such local handling reduces the cost of providing communication services within the group.
  • PSTN public switch telephone network
  • PBXs also provide other advantages, such as call blocking to specific numbers or groups of numbers. Call blocking, in such case, may be used by a PBX operator to prevent long-distance calls from specific telephones or groups of telephones within the private system.
  • Cellular communication systems are also known.
  • Cellular communication systems as opposed to PBX systems, are constructed to provide communication services over broad geographic areas through a number of base sites.
  • Each base site within such a system is positioned to provide service within a service coverage area, partially overlapping adjacent service coverage areas, in such a manner as to provide substantially continuous coverage to a communication unit passing through such an area.
  • Communication service within a cellular system, is provided to a communication unit on a radio channel selected from a number of communication channels (fl-fn) available within the system. Such radio channel are assigned to communication units upon request.
  • Cellular communication systems are typically interconnected with the PSTN either locally, through an interconnect at each base station, or centrally, through a mobile switching center (MSC) that interfaces with a number of base sites.
  • the interconnect with the PSTN allows a communication unit to communicate with subscribers throughout the PSTN as well as other communication units.
  • the interconnect with the PSTN also allows a communication unit to communicate, through PBXs with telephone users within a PBX.
  • a private wireless system may find it advantageous to use cellular channels, the private wireless system may have to coexist with existing cellular facilities.
  • Such a wireless PBX communication system may have to be able to select channels also being used by a local cellular system. Because of the importance of PBXs and the need for wireless communication within a PBX environment a need exists for a means and method, of selecting cellular channels for use by a wireless PBX system, that is non-interfering with the cellular system.
  • a method and apparatus for identifying network communication resources.
  • the method includes the steps of measuring a signal quality factor of a channel of a selected spectrum and comparing the measured values with a threshold value.
  • the method further includes the step of selecting channels, exceeding the threshold, as network communication resources.
  • the selected spectrum is that, also used, by a local cellular communication network. Where scanning and threshold comparisons indicates that a channel is not being used by the cellular system then use is permitted within the private system.
  • FIG. 1 illustrates, in block diagram form, a private branch exchange including a wireless communication facilities in accordance with one embodiment of the invention.
  • FIG. 2 illustrates, in block diagram form, a wireless intercept box in accordance with the invention.
  • the solution to the problem of channel selection within a PBX wireless communication system lies, conceptually, in the use of a scanner and in the evaluation of communication resources based on signal measurements by the scanner. Resource evaluation is based upon comparison of signal measurements on scanned resources with a threshold value.
  • the use of a scanner allows candidate resources to be evaluated for interfering users before use is permitted within the PBX wireless system. Scanning, under such a format, may be of an entire spectrum with the results reported, en masse, to a wireless controller or scanning may be of individual resources under the control of the wireless controller with individual signal measurements reported back to the wireless controller for comparison with the threshold.
  • the reader's attention will first be drawn to a description of function of a wireless PBX system. Following the description of function, channel selection will be described in accordance with one embodiment of the invention.
  • FIG. 1 illustrates, in block diagram form, a PBX system, generally (10), offering wireless communication services in accordance with a preferred embodiment of the invention.
  • a PBX switch 11
  • WIB wireless interface box
  • signaling interface 13
  • scan receiver controller 14
  • scan receiver (19)
  • base stations 15-18 Also shown in FIG. 1 are communication units 20-22.
  • PBX communication system 10 is constructed to have the functionaHty of routing telephone calls among subscribers (103) and external, PSTN subscribers (not shown) and among subscribers (103).
  • a call from a wireline subscriber (103) to another wireline subscriber (103) is accomplished through interconnects (102) under prior art methods within the PBX switch (11).
  • Calls between an external, PSTN subscriber and wireline subscriber (103) is also accomplished under prior art methods within the PBX switch (11).
  • Some subscribers (103), in accordance with one embodiment of the invention, have a dual service capability including the capacity of receiving (and making calls) through either wireline or wireless facilities.
  • Such subscribers (103) receive wireline service through a wireline facility at a fixed location (e.g., a telephone within an office) or through a wireless transceiver (20-22) carried by the subscriber (103).
  • the WIB (12) provides the functionaHty of forwarding calls directed to a wireline subscriber on a wireline (e.g., 106) to a wireless receiver (e.g., 20) after a fixed delay.
  • a call may be routed first to the wireless subscriber and then, after a delay, to the wireline subscriber.
  • the fixed delay aUows for receipt of the call at the fixed location (through wireline 106) before transfer to the wireless communication unit (20) through the WIB (12) and a base station (15, 16, 17, or 18).
  • Coupling between WIB (12) and base stations (15-18) is accompHshed via signaHng links 100, incorporating a wireless-related signaHng protocol, and via subscriber links 101.
  • Communication units 20-22 and base stations 15-18 are constructed to exchange communicated messages at low power levels (e.g., 10 milliwatts) under a prescribed signaling protocol such as, for example, that used in the Advance Mobile Phone Service (AMPS) cellular radiotelephone service.
  • AMPS Advance Mobile Phone Service
  • communication units 20-22 upon activation, scan a spectrum seeking a signal from any of base stations 15-18 for service through the PBX wireless system (10).
  • the single antenna (19) of base stations (15-18) is comprised of a distributed antenna network (23) coupled to the base stations (15-18) through a combiner (not shown). Also coupled to the distributed antenna network (23) through the combiner is the scan receiver (19).
  • the independent antenna of the distributed antenna (23) are located throughout a service coverage area of the PBX system (e.g., a floor of a building). Other distributed antenna (23) may cover the same, or other floors.
  • the distributed antenna (23) simplifies system design in that wireless subscribers (20-22) may progressively transceive through different antenna of the network (23) as the subscriber (20-22) moves through a coverage area of a base station (20-22).
  • the distributed antenna (23) allows operation of the PBX wireless network (10) without the compHcated process and associated hardware required by handoff from base station to base station.
  • FIG. 2 generally depicts, in block diagram form, WIB 12.
  • wireline group 104 enters a time slot interchange (TSI 218).
  • TSI 218 may be a time slot interchange as that having part number 8980, and manufactured by MITEL® (MITEL is a registered trademark of MITEL Corp., a subsidiary of British Telecom).
  • MITEL is a registered trademark of MITEL Corp., a subsidiary of British Telecom
  • TSI 218 is also coupled to subscriber links 101 which interconnects WIB 12 to base stations 15-18.
  • TSI 218 is interconnected to I/O) controUer
  • Processor 206 is coupled to a data store (209) which stores, inter alai, slot-to-slot connection data and subscriber line- to-wireless subscriber number translation.
  • processor 206 is coupled to a program store (212) which stores programs used by processor 206 to perform, inter alai, TSI control, signal digit analysis, and ring detection.
  • Processor 206 is coupled, via I/O controUer 203, to the signaling interface 13.
  • Signaling interface 13 provides the requisite interface for signaling links 100 to inter-couple WIB 12 to base stations 15-18.
  • Signaling interface 13 accepts signaling information, from processor 206 from a selected line of wireline group 104, and uses this information for its own control and for generating the appropriate signaling messages for subscribers, for example, wireless subscriber 20. In addition, signaling interface 13 transmits and receives information to from base stations 15-18. This data is primarily information which will be sent, or has been received, on a control channel, but the information content may be expanded as required. In the preferred embodiment, the type of signaling used in the system is analogous to that used in the AMPS ceUular radiotelephone system. In alternate embodiment, signaling links 100 may carry information using a message based protocol between signaling interface 13 and base stations 15-18. Implementation of signaling interface 13 may be reaHzed by employing any conventional micro-computer system. As such, in this embodiment, signaling interface 13 would also be able to maintain caU records and statistics as required based upon the passage of information.
  • Base stations 15-18 of FIG. 1 each transmit overhead information, pages, and appropriate channel assignments to wireless subscribers (20-22), such as wireless subscriber 20.
  • base stations (15-18) receive page responses and caU origination requests from wireless subscribers (20-22).
  • SignaHng links (100) can carry the above-mentioned information (between base stations (15-18) and WIB (12)) in the actual protocol message form as required by the wireless system, or it can be in any of the data link protocols (e.g., high-level data link protocol
  • WIB 12 has the capability to monitor the data stream of individual trunks from trunk group 109.
  • trunk group 109 consists of a 24 channel pulse coded modulated (PCM), 1.544 megabit per second (Mbps), (DS1) service.
  • PCM pulse coded modulated
  • Mbps 1.544 megabit per second
  • DS1 DS1 service.
  • the least significant bit of every sixth DSO slot contains signaling information pertaining to trunk seizure, caUed number, disconnect, etc.
  • Signaling information, from trunk group 109 is assembled in message format and is transferred to signaling interface 13 using a protocol such as HDLC.
  • the message content can be set-up in a "1" or "0" format for interpretation in signaling interface 13.
  • CaU deHvery to subscriber 103 is as foUows in accordance with the invention.
  • a caU from an originator for example, from the PSTN
  • the PBX (11) routes the call to wireline 106 as in the prior art.
  • the WIB (12) detects a seizure (ring signal) for wireline subscriber 103 (on wireline 106) and begins a time delay. After a fixed delay the WIB (12) determines the corresponding mobile phone number of wireless subscriber 20 and passes this information to signaling interface 13 via I/O controUer 203 in the form of the actual signaling protocol (e.g., the HDLC link protocol).
  • Signaling interface 13 then generates a paging message which is sent, via signaling links 100, to aU base stations 15-18 for transmission to wireless subscriber 20. If one of base stations 15- 18 is busy handling an existing caU, the busy base station will discard the information. If a base station (15-18) is idle, it wiU transmit the page as part of a control channel stream along with a system identification code to which wireless subscriber 20 attaches an association. AU base stations (15-18) may carry the same identifier, or different base stations may carry unique identifiers so as to differentiate a service or coverage areas. The wireless system also supports sleep-mode operations for idle subscriber units (20-22).
  • the PBX 12 While signaHng information is being routed to base stations 15-18, the PBX 12 receives information from the PSTN as it would for any wireline caU, and sets-up the caU accordingly. The information is routed, through TSI 218, to the base stations 15-18 via subscriber links 101. Upon receipt, base stations (15-18) intercept the ring signal while continuing to monitor the radio- frequency (RF) channel for a response to the page.
  • RF radio- frequency
  • Wireless subscriber 20 upon receipt of the page, responds on an RF channel corresponding to an idle base station (15-18) within the system (10).
  • the idle base station e.g., 17 which receives the response, from wireless subscriber 20, wiU direct WIB 12 to assign the appropriate line (110) from subscriber links 101 to be interconnected with the appropriate line (106) from wireline group 104 via TSI 218.
  • the now-communicating base station (17) sends an alert to wireless subscriber 20, resulting in a ring signal.
  • the now communicating base station (17) wiU send an off-hook signal by way of subscriber links 101 (via WIB 12) to PBX 11 so as to provide the final connection and estabHsh communication from the originator to wireless subscriber 20.
  • CaU origination from wireless subscriber 20 to a destination is accompHshed as foUows.
  • wireless subscriber 20 When not in use, wireless subscriber 20 resides on an idle channel that is transmitting idle protocol. Wireless subscriber 20 monitors the protocol until such time as the protocol is lost or wireless subscriber 20 begins placing a caU. At such time as base stations 15, 16, 17, or 18 detect an origination attempt, by wireless subscriber 20, the corresponding base station 15, 16, 17, or 18 wiU drop the idle channel protocol and connect through to the PBX 11 via WIB 12, and more specificaUy, via signaling links 100.
  • PBX 11 wiU prepare to receive the caU from wireless subscriber 20 by connecting subscriber 20 from wireline group 104 to base station 15, 16, 17, or 18 via the appropriate line of subscriber links 101. At this point, wireless subscriber 20 can send dialing information in one of two ways.
  • the origination message sent by wireless subscriber 20, does not contain calling information and the origination message simply seizes an RF channel for a caU.
  • the corresponding base station 15, 16, 17, or 18 connects to PBX 11 by way of subscriber links 101 and waits for a dial-tone.
  • wireless subscriber 20 Upon hearing a dial-tone, wireless subscriber 20 begins using any standard dialing protocol, such as dual-tone multi-frequency (DTMF)
  • DTMF dual-tone multi-frequency
  • a base station 15, 16, 17, or 18 receives aU the necessary calling information in the origination message.
  • the corresponding base station 15, 16, 17, or 18 then goes off-hook.
  • the corresponding base station 15, 16, 17, or 18 couples to wireless subscriber 20 and, at this point, the caU may proceed as a normal wireline caU Channel selection, in accordance with the invention, and for assignment to the wireless subscriber (20), is performed by the processor (206) based upon measurements performed by the scan receiver (19).
  • the processor (206) directs the scan receiver (19) to scan channels, also used by the local ceUular radiotelephone system, for purposes of identifying channels usable within the PBX wireless system (10).
  • the processor (206) directs such scanning through commands generated within the processor (206) and transferred to the scan receiver controUer (14) through the I/O controUer (203) and signaling interface (13).
  • the scan receiver controUer (14) in turn, directs scanning of channels by the scan receiver (19) based upon commands received from the processor (206).
  • the scan receiver (19) upon scanning channels, returns a signal quaHty factor (such as a received signal strength indicator (RSSI)) to the processor (206), through the scan receiver controUer (14) for each scanned channel.
  • Signal quaHty factors are returned, along with a channel identifier, to the processor (206) through the signaling interface (13) and I/O controUer (203).
  • the returned signal quaHty factors are compared, within the processor (206), with a threshold value. Channels having a signal quaHty factor exceeding the threshold are deemed to be usable channels within the wireless system (10).
  • a Hst of usable channels is created within the data store (209) of the WIB (12).
  • the processor (206) may select a usable channel from the list within data store (209) for assignment to the wireless subscriber (20-22). In advance of assignment the processor (206) may direct the scan receiver (19) to again scan the channel in anticipation of assignment. Channels that are found usable are assigned. Channels that are found not to be usable are removed from the Hst.
  • Channel scanning may also occur on channels used by the base stations (15-18) for the transmission of control information.
  • Such scanning would occur at regular intervals to insure reUable operation of the wireless PBX system (10).
  • base stations (15-18) would change channels for transmission of control information.
  • Channel scanning and reuse of ceUular channels within the PBX wireless system (10) beneficially allows for improved communication within localized area such as shopping malls, factories, or sports facilities.
  • Such reuse by private systems offers the advantage of mobile communication in areas that by their nature may limit interference to nearby cellular systems.
  • Such limited interference occurs because of the use of distributed base stations antennas and low power levels between base station and wireless unit.
  • the private system may coexist on the same channel or set of channels within the same system without significant mutual interference within the private system or the local ceUular system.

Abstract

Dans un réseau de communication (10) sans fil PBX à installation d'abonnés (11), un procédé et un appareil sont utilisés pour identifier les ressources de communication du réseau. Le procédé comprend les étapes de mesure du facteur de qualité des siganux d'un canal d'un spectre choisi et de comparaison des valeurs mesurées avec une valeur de seuil. Le procédé comprend de plus l'étape de sélection des canaux excédant la valeur de seuil, en tant que ressources de communication du réseau. Le spectre sélectionné est celui qui est aussi utilisé par un réseau de communication cellulaire local. Lorsque le balayage détermine qu'un canal n'est pas utilisé par le système cellulaire, son utilisation est alors permise avec le système privé.
PCT/US1993/006226 1992-08-03 1993-06-30 Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux WO1994003993A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP6505300A JPH07504555A (ja) 1992-08-03 1993-06-30 チャネル識別に周波数走査器を使用する無線ｐｂｘシステム
EP93916873A EP0614589A4 (fr) 1992-08-03 1993-06-30 Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux.
BR9305595A BR9305595A (pt) 1992-08-03 1993-06-30 Processo e aparelho para identificar recursos de comunicação de rede
FI941503A FI941503A0 (fi) 1992-08-03 1994-03-30 Langaton puhelinvaihdejärjestelmä, joka käyttää taajuuspyyhkäisintä kanavan määrittämiseksi

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92366392A 1992-08-03 1992-08-03
US07/923,663 1992-08-03

Publications (1)

Publication Number Publication Date
WO1994003993A1 true WO1994003993A1 (fr) 1994-02-17

Family

ID=25449055

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1993/006226 WO1994003993A1 (fr) 1992-08-03 1993-06-30 Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux

Country Status (7)

Country Link
EP (1) EP0614589A4 (fr)
JP (1) JPH07504555A (fr)
BR (1) BR9305595A (fr)
CA (1) CA2118717A1 (fr)
FI (1) FI941503A0 (fr)
MX (1) MX9304686A (fr)
WO (1) WO1994003993A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5475735A (en) * 1993-12-02 1995-12-12 Motorola, Inc. Method of providing wireless local loop operation with local mobility for a subscribed unit
WO1996039786A2 (fr) * 1995-06-05 1996-12-12 Telefonaktiebolaget Lm Ericsson (Publ) Equipement fournissant un complement de mobilite pour le reseau telephonique public commute
WO1997000589A1 (fr) * 1995-06-19 1997-01-03 Ericsson Inc. Stations de base multi-utilisateurs et procede de fonctionnement
WO1998034428A2 (fr) * 1997-01-30 1998-08-06 Nokia Telecommunications Oy Attribution de voies dans un systeme de communications mobile
EP0872127A1 (fr) * 1995-09-08 1998-10-21 At&T Wireless Services, Inc. Systeme cellulaire sans fil
WO2000019754A1 (fr) * 1998-09-25 2000-04-06 Siemens Aktiengesellschaft Sous-systeme interne dans un reseau radiotelephonique mobile
GB2364857A (en) * 2000-07-14 2002-02-06 Ip Access Ltd Controlling frequency and time offset of base station transmissions; selecting channels and transmission powers
GB2443865A (en) * 2006-11-10 2008-05-21 Siemens Ag Interference control between local and network base stations

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4790000A (en) * 1985-12-11 1988-12-06 Hitachi, Ltd. Portable radio telephone system
US5040238A (en) * 1990-06-29 1991-08-13 Motorola, Inc. Trunking system communication resource reuse method
US5210786A (en) * 1986-10-15 1993-05-11 Iwatsu Electric Co. Ltd. Portable telephone system using stratified exchange system
US5212805A (en) * 1990-06-29 1993-05-18 Motorola, Inc. Near-field on-site/trunking system frequency sharing

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5142691A (en) * 1991-04-05 1992-08-25 Motorola, Inc. Frequency management system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4790000A (en) * 1985-12-11 1988-12-06 Hitachi, Ltd. Portable radio telephone system
US5210786A (en) * 1986-10-15 1993-05-11 Iwatsu Electric Co. Ltd. Portable telephone system using stratified exchange system
US5040238A (en) * 1990-06-29 1991-08-13 Motorola, Inc. Trunking system communication resource reuse method
US5212805A (en) * 1990-06-29 1993-05-18 Motorola, Inc. Near-field on-site/trunking system frequency sharing

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0614589A4 *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5771453A (en) * 1993-11-04 1998-06-23 Ericsson Inc. Multiple user base stations and methods for radio personal communications systems
US5475735A (en) * 1993-12-02 1995-12-12 Motorola, Inc. Method of providing wireless local loop operation with local mobility for a subscribed unit
WO1996039786A2 (fr) * 1995-06-05 1996-12-12 Telefonaktiebolaget Lm Ericsson (Publ) Equipement fournissant un complement de mobilite pour le reseau telephonique public commute
WO1996039786A3 (fr) * 1995-06-05 1997-02-06 Ericsson Telefon Ab L M Equipement fournissant un complement de mobilite pour le reseau telephonique public commute
US5771465A (en) * 1995-06-05 1998-06-23 Telefonaktiebolaget Lm Ericsson Apparatus for providing a mobility adjunct for the public switched telephone network
WO1997000589A1 (fr) * 1995-06-19 1997-01-03 Ericsson Inc. Stations de base multi-utilisateurs et procede de fonctionnement
EP0872127A4 (fr) * 1995-09-08 2001-04-11 At & T Wireless Services Inc Systeme cellulaire sans fil
EP0872127A1 (fr) * 1995-09-08 1998-10-21 At&T Wireless Services, Inc. Systeme cellulaire sans fil
WO1998034428A2 (fr) * 1997-01-30 1998-08-06 Nokia Telecommunications Oy Attribution de voies dans un systeme de communications mobile
WO1998034428A3 (fr) * 1997-01-30 1998-12-17 Nokia Telecommunications Oy Attribution de voies dans un systeme de communications mobile
US6466794B1 (en) 1997-01-30 2002-10-15 Nokia Telecommunications Oy Channel allocation in a mobile communications system
WO2000019754A1 (fr) * 1998-09-25 2000-04-06 Siemens Aktiengesellschaft Sous-systeme interne dans un reseau radiotelephonique mobile
GB2364857A (en) * 2000-07-14 2002-02-06 Ip Access Ltd Controlling frequency and time offset of base station transmissions; selecting channels and transmission powers
GB2364857B (en) * 2000-07-14 2004-12-29 Ip Access Ltd Cellular radio telecommunication systems
GB2443865A (en) * 2006-11-10 2008-05-21 Siemens Ag Interference control between local and network base stations

Also Published As

Publication number Publication date
FI941503A (fi) 1994-03-30
MX9304686A (es) 1994-03-31
BR9305595A (pt) 1996-01-09
EP0614589A1 (fr) 1994-09-14
FI941503A0 (fi) 1994-03-30
CA2118717A1 (fr) 1994-02-17
EP0614589A4 (fr) 1995-01-04
JPH07504555A (ja) 1995-05-18

Similar Documents

Publication Publication Date Title
US4879740A (en) Wide area cordless telephone system having means for avoiding double registrations
US5771275A (en) Use of ISDN to provide wireless office environment connection to the public land mobile network
US5787355A (en) Method and apparatus for wireless trunking to private branch exchanges
US5440613A (en) Architecture for a cellular wireless telecommunication system
KR100262370B1 (ko) 확산 스펙트럼 무선 전화 시스템
US5345597A (en) Call set-up in a radio communication system with dynamic channel allocation
US6330448B1 (en) Handover arrangement for mobile station moving across the boundary of wireless cell-site stations of adjacent PBXs
EP0398911B1 (fr) Systeme de communication interurbain avec capacite d'acces nationale
US5239676A (en) Intra-cell call hand-over in radio communication systems with dynamic channel allocation
FI116353B (fi) Järjestelmä ja menetelmä, jotka liittyvät solukkoteleliikenteeseen
US5590172A (en) Method and system for transferring a radiotelephone call from one coverage area to another
FI103169B (fi) Menetelmä tietoliikenneyhteyden muodostamiseksi
EP0583137B1 (fr) Architecture pour système de télécommunications cellulaire "sans-fil"
EP0605086B1 (fr) Petit système de télécommunications "sans fil"
WO1994003993A1 (fr) Systeme sans fil pbx d'installation d'abonnes privee utilisant un balayeur de frequence pour l'identification des canaux
AU6128296A (en) Communication system and call establishment methods
US6640100B1 (en) Radio communication system
CA2100621A1 (fr) Systeme de telecommunication
WO1993020642A1 (fr) Appareil et methode de desserte d'abonnes en radio-telephonie dans un environnement de lignes filaires
JPH03129944A (ja) 構内交換の機能を達成する通信システム
KR100327163B1 (ko) 무선 가입자망 단말기의 알 에프 모듈 공유방법
KR100540568B1 (ko) 시 디 엠 에이 망에서 팩스및 데이타 정보 자동 수신 지정방법
KR0150590B1 (ko) 이동통신시스템 기지국 및 기지국의 내선 호 제어방법
KR19990075870A (ko) 무선가입자망 시스템내 기지국 제어기의 트래픽 교환방법
KR20010009001A (ko) 디지털 주파수 공용 통신 시스템에서의 공중 교환 전화망 접속장치 및 그 방법

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA FI JP

AL Designated countries for regional patents

Kind code of ref document: A1

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

WWE Wipo information: entry into national phase

Ref document number: 2118717

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 941503

Country of ref document: FI

WWE Wipo information: entry into national phase

Ref document number: 1993916873

Country of ref document: EP

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWP Wipo information: published in national office

Ref document number: 1993916873

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1993916873

Country of ref document: EP