CA2015932C

CA2015932C - Mobile communications system

Info

Publication number: CA2015932C
Application number: CA002015932A
Authority: CA
Inventors: John Leonard Adams; Vincent Joseph Skinner
Original assignee: British Telecommunications PLC
Current assignee: British Telecommunications PLC
Priority date: 1989-05-03
Filing date: 1990-05-02
Publication date: 1999-04-13
Anticipated expiration: 2010-05-02
Also published as: JPH03205928A; JP2517697B2; FI98685C; ES2076310T3; HK142196A; US5168498A; FI98685B; EP0426269A1; AU625703B2; DE69021685D1; DE69021685T2; AU5477790A; FI902163A0; GB8910085D0; ATE126646T1; CA2015932A1; EP0426269B1

Abstract

A system for mobile communication includes a number of base stations. Associated with each base station is an interface unit which packetises voice information and includes header information concerning user and destination addresses. These interface units tracks the movement of the various user by passing control blocks from interface unit to interface unit. Packets are routed via a routing block and switches. The stored information within the base station interfaces allows movement from one base station to allow to be handled without call loss.

Description

CA 0201~932 1998-12-16 MOBIT~ CO~UNICATIONS SYST~MS
Fiel~ of the Tnvention The invention relates to a mobile communications system and more particularly to the control and structure of such systems.

Backgrolln~ to the Tnvention In known digital cellular radio configurations represented by Figure 1, the system comprises a number of base stations 10, 13, 16 each of which are connected to a local exchange for mobile systems 11, 14 and 17 (i.e. mobile switching centres).
The blocks 11, 14 and 17 are connected to the telco (e.g.
British Telecom) network via switches 12, 15 and 18 which allow communication with geographically remote users via switches 22, 25 and 28, exchanges 21, 24 and 27 and base stations 20, 23, 26. To illustrate operation mobile telephone users 30, 31 are shown communicating with telephone users 46 and 45 respectively.

Users 30 and 31 happen to be using the same base station 13, and users 45 and 46 are using geographically adjacent stations 23. The active exchanges 14 and 24 will pass the voice information between the users and will also provide location control information which voice and control information will pass as packets of digital data through the telco network (which may include digital exchanges 15 and 25 with optical fibre interconnections).

When a user (say user 30) who is on the move passes closer to one of the base stations 16, the system has the capability to switch communications to the geographically closer base station and in practice the user's telephone will request the base station to accept transmission and this will be handled by the exchange 127 to ensure the call is routed to the correct destination. This will require the switch 18 to link with switch 25 (as shown by the broken line connection).

CA 0201~932 1998-12-16 With increasing popularity, because of greater density of traffic use, the Figure 1 configuration becomes saturated when the number of users either initiating a call or moving to other S base stations is high.

In a Globecomm 88 paper titled 'The ATM Zone Concept' by Foster and Adams, a possible solution is described which employs a network architecture based on ATM (Asynchronous Time Multiplexing).

Summary of Invention The present invention is concerned with a mobile system with improved capabilities which can make use of this zonal concept.
According to the invention there is provided a mobile communications system including: a plurality of base stations, routing means for connecting any base station to any other base station, a plurality of means each associated with one of said base stations for packetising control and packetising data signals and a plurality of means each associated with one of said base stations for tracking the current physical address within a packet switched network of a moving terminal to which control and/or data packets are to be passed and from which control and/or data packets are received.

Further according to the invention there is provided a method of controlling a mobile communications system having a plurality of base stations, the method comprising: providing a routing path for connecting any base station to any other base station, providing at each station packetising control information and packetising data information and providing at each station tracking of the current physical address within a packet switched network of a moving terminal to which control and/or data packets are to be passed and from which control and/or data packets are received.

CA 0201~932 1998-12-16 =~

Rr;ef Description of Drawings:
The invention will now be described by way of example with reference to the accompanying drawings in which:
s Figure 1 shows a known mobile communication system;

Figure 2 shows an embodiment of the present invention;

Figure 3 shows the asynchronous transfer mode (ATM packet structure;

Figure 4 shows the base station and associated interfacing of Figure 2 in more detail;
Figure 5 shows the network switches in Figure 2 in more detail;
and Figure 6 shows one configuration for the router 40 of Figure 2.
Description of the Preferred ~mhodiment In Figure 2 a system is described which removes the need of the exchanges 11, 14, 17, 21, 24, 27 of Figure 1 and provides a distributed system of suitable intelligence to handle control information locally.

Associated with each base station is a control interface unit lOa, 13a, 16a, 20a, 23a, 26a. The users 30, 31 will communicate to the base station 13 and digital voice signals and other information therefrom will pass to the control interface 13a which will generate control information and packetised voice information which will pass via routing block 40 (which is a cross connector/concentrator) and switches 50 and 52 to routing block 41 (also a cross connector/concentrator) to base stations 23 via control interface 23a. In addition to generating control information, the ~nterface 13a wi~l generate a pscketised voice de~tination address for each u~er to be received by the in~erface boa~d 23a of the associated remote user. This destination add~es~
a~co~panying the voice packet allows ~he switches ~0 - S2 to determine how to route the call to ensure receipt at the co.-L~cL destinatlon. As can be seen from Flgure 3 the voicelcontrol information is carried in packet form ~ith the de~tination address in the packet header. The sW~t~
effec~ed b~ switches 50 - 52 is ba~ed solely on the destination addres8 value.

Traffic flexibil1~y is ach~eved by using Asynchronous Transfer Mode (ATN) t~hni~ues.

The connection of a number of ba~e ~tations to ~n ATM ~wl~ching node may be achleved using ~ pas~ive opti~al network (PON) tree and branch ~tructure. Other structure~ are not precluded, eg a ring 8tructure. ~f each PON is as~igned a sin~le addre~8 for d~stinat~on-routed ATM packets then, on arrival at the d~Bt~nation PO~, such packets will be broadcast to all bafie stationB attached to the PON. The further identif~cAtlon Of which ATN packets are associa~ed with a giv~n base station comes from the connection number stored in a separate 16-bit field in each packet.

A~ shown in Pigure 3 the ATM packets include an information fleld and a header. A connection number would be contained ln the information field together wit~ the voice information. In ~he header a header error control field (HEC) and a aestination addre8fi ~ield ~ provided. The d~stination address f~eld may con~ist of two part~ ie. the ~irtual Path Identi~ier (YP~) and the Virtual Ch~nnel Xdentifier (VCI). The VPI partitions any A~N packet str~am into a num~er of separate payload~. It may be ussd to distinguish between payload~ with differ$ng quality x of service requirements (ie di~feren~ tolerances to packet lo&s rates and end-to-end delay) and has a limited capability to distinguish between ~ayloads requiring separate routes. The size of the VPI fleld and its uses in the target B-I ~ N
(~n~egrated Sy~tem ~igital Network) are the sub~ect of ~uch current discussion in standards bodies but could typlcally be 8 bits ( See also J L Adams I The Virtual Path Identi~ler and ~ts ~rpl ;c~tions for Routeing and Priority Of Connect~l~nless and Connection Oriented Services', International Journal of ~lgital and Analog Cabled Systems. 1989).

To obta~n destination addressing of hundreds-of-tht~ n~R of PONS located over the whole of the UK, for example, as would be requ$red beyon~ the year ~OOO, it is propo~ed th~t a few VP~
values are reserved (eg 8 values). Each VPI value repre~ents one address 'blockl o~ 64k addresse~ as speci~ied by the value in the 1~ bit VCI field. The total address space, which ~ an integer multiple of ~4k, can be con~idered an aTN zone.

Half o~ the reserved VPI values are used to ca~ry 9~g~Al l~ng information, and such packe~s will al50 carry a higher prior~ty through ~he ATM net~ork (ie such packets will be le58 likely to be discarded). This de~ines a s; gn~ g path in both dlrectlons between ~he two current destinations of the c~ ng and called cu~tomers o~ any ~iven connection. This s~n~ ng chAnnel is configured to ~e a high capac~ty (br~h~
bit-rate) Ghannçl capable of transferring informa ~on quickly between the two ends ( eg for a l~ookm route through the A~N
network, the mean one-way delay including ~C~tl-~Ation ls about 10 ms ). When not in use, the chAnnPl capacity can be temporarily a~-~igned to other user~ according to ~nown VPI
mul tip1 exing principles . Additional signA~ ng pathB QXist bet~--cn ~ base station and controllers s~sewhere ln the network, the path~ ~eing identified by suitable s~n~ ng ~PI

~ 2~59~?~

values plus particular VCI values. The remaining reserved VPI
~alues are used to carry voice packets base statLon-to-base station with no change to the packet header.

PON des~ination ad~re~es operate a~ group addrQsses, ie the address a6signed to each Po~ is also valid for all other PON~s which have ad~acent cells. At the ATN cross-connect (block~ 40 and 41 of Figure 2 ) ATM packets carrying a group addres~ are automatically b~oadcast to all the relevant PONS.

The other aspects of packet hand~ing can be ba6ed on techn~qu~s disclosed in European Patent Public~tion No. 16a265~

The purpose of router 40 is to allow concentration of a number of geographically adjacent base stations 10, 13 and 16 to pass to the one switch 50 and also to act as a cro~R cQnnqc~or ~0 allow gpeech and information destined for base stations }3 to pass also to base ~tations lo and 16. This allows a user 30 ~or example to move away from ba4e ~tation 13 towards 16 and that base station to take over the com~unication role wi~hout loss of th~ call occuring. Block 40 would be repl$ca~-ed using ba~e stat~ons 1~ as the upper set of ~a~e stations and further base stat~ons (not shown) would be connected to this to deal with movement away from 16 to lower stations.
~en~e the sy~tem i~ fl~xible enough to deal with caller~ ~ovlng - from one base station to another within the duration of the call and the ~nterfacing has the capabili~y of mapplng the location# of the remote user~ to ensure correct routing of ~he calls. The cell size normally used for mobile communlcations can conveniently be reduced to mini-cells by using this te~hn;que (e~g. 100 metres radius) ~o that the number of u~ers per cell fall~ to ~educe conge~tion in high traffic deEand areas. This increase in the number of cells result~ng therefrom i8 not a disad~antage as regards switching be~ e of the ~implifled switching/routing mechani6ms propo~ed and the fa~ter tracking feature6 of destination addre-~sing.

The conf~guration of Figure 2 described above providos base station-to-base ~tation control o~ tracking. This removes processing load from a central controller and hence removes ~
potential proces~ing bottleneck particul~rly as the sy~tem evolves towards ~he greater use of microcells. As either customer moves the ATM Zone automaticall~ provide~ a new volce path and a new path for the tran~fer Of 81 g~ ng information. There i8 minimal delay and minimal processing load in~olved ~n Yetting up a di~ferent path since the route to any glYen de~tination is already pre-determined. ~he c~p~lty previou61y used on the lold' path and no longer required i8 automatically made availa~le to o~her users according to VPI
multiplexing principles.

De~tination addressing also si~plifies the data transfer for connectionless services as in mo~ile terminals.

a configurat~on ~or dealing with the information at ~ase 8tation level i~ ~hown in Figure 4.

one of the ba~e station interface units 13a is ~hoNn which has a kase ~tation connection 73 for voice ~h~nn~l n and a connection 74 for the base station s.ign~ll in~ ch~nn~l . A
connection 75 is provided for voice packets and a connection 76 for signAl1i ng associated with the packets which are ~onnP~ted to the routing block 40. The connection 73 passes wlthin the interface 13a to a packetiser/depacketiser 6~ which will take digital voice information from the voice rhAn~Pl~ ~nd packetlse them in block 69 for passa~e to the voice packet ~ueue within router 40. A packet counter 70 will count oùtqo~ng packet~ and provlde the count and the connection number ~ssociated With the pa~kets to allow charg m g information to be calculated in block 7~ under the ~ontrol of ~icroprocessor 61. The mi~ O~LOC&3SOr 61 will also ~a~e access to base station signalling information from connect~on 74 and packetised sign~ g information from th~ remote st~tions via packetiser/de~Hc~etis~r 6~. ~he micLoprc~es~or will route inform~t~on on the free connection number~ ~or store h2 and customs ~den~ity informatlon for store 63~ It will also deal with the terminal~s own PON addre~s for store 64, the destination PON addre~s for store 65, the connection number for store 66 and the ~anchor~ add~e~s for ~tore block 67. The connection num~er store 66 wi~l deter~lne, dependent on st~red in~ormation, whether the pac~etised incoming information is discarded by deFa~ketiser 6g or not, to pr~en~ unwanted packet~ bsing retained~

Thus for each mobile terminal ~urrently associ~ted wlth a particular cell/microcel~, all of the base stations within its group address will store that terminal~s current PON address, current de~t~nation PON addres~/ and connection number, together with the ~anch~r~ oontroll~r addres6 ( e~rl A i ne~
below). This in~or~ation is loaded into ta~les at ea~h ba~e station by a broadcast message from the opp4s~te end, ~e each end of a call in progress is re~ponsible for updating the group tables of the other end.

T~e me~hAn~m ror updating group tables is triggered whenever a terminal move to an adjacent cell, m1ni~ell, or mlcrocell. In th~s case the new base station will send a s~ ~n~l 1 lng meSBage to the ad~ress of the de~tination PON, contain~ng the cu~tomer ldentity at both ends, the ~anchor~ controller addre~sl the dest~natlon PON addre~s, and information on the updated near-end PON address and connection nu~ber, if ~he ~alu~s of these parameters have changed. In response ths base station a~ocia~ed with the terminal a~ the other end will send lts "__ 2~ ~9~J~

current values of the same li~t of parameter~ rega~dle~s of whether there have been any changes or not.
Connect~on numbers need to be changed whenev~r there i8 a change in the PON address~ Connection number blocks cont~ni~g free connection numbers can be pre-as~igned to each base station ln a PON group 80 that the selection o~ ~ n~w connection n~ber can be made autonomously b~ any ba~e station as ~he ter~inal ~oves from PON group ~o PON group.

~T~ packetisers at the base stations autom~tically load the destination PON addre~s into the headers of voice ~P~et~.
This is the only action required ~o route the packet. Packet counters a~e used at the base stations for the purposes of ~harging. On moving to a new base station, t~e 'old' base station sends charging information using ATN si~nAll~ng packets with a destlnat~on address set the ~anchor~ controller. Thls controller {s the only fixed point in ~he architecture, hen~e the name ~anchor~. Many replicas of the ~anchor~ controller exl~t within ~he Zone, and one of them becomes associated with a giYen ca~l at the tLme of call set-up. Its identity then remain~ fixed throughout the call. Using the Zone c~r.~ an ATM route always exists to any ~anchor~ controller frcm any ba~e station.

Ma~ntenance and policing m~ al~o be included a~ control function~. Tech~i~AI eq~ipment compatible with the G~ tGroupe ~~e~tAle Nobile - pan European net~ork) System may be u8ed.

As eYrl~ d with relation to Figure 2, the switches 50 - 52 are ~p~hle of handling ~he in~ormation generated by the ba~e ~tations and associated interface and these in practice would be part of a larger network of ~witches (typically nationwide). The switche~ could be configured as shown in ~igure 5~

. CA 0201~932 1998-12-16 .~. .

One of the switches 50 is shown with an incoming packet connection 85 for receiving packets from router 40 or from another switch 51. A fault condition input 86 is also provided to indicate faults on any given route. Packets from the switch 50 are available for passage at connection 87.

Arriving packets within switch 50 pass to a first-in, first-out store (FIFO) 90. Destination address information within the packet header is av~ hl e to the header translator 91. This information includes the VPI and VCI numbers. This information is used by the header translator 91 in association with the preferred route block 92 to determine from the stored route information what is the most preferential route to be chosen and this switch header information is made available to the main switch block 93 which switches the information field from the FIFO 90 in appropriate manner. After switching, the information field passes to FIFO 95. The switch header information passes to a header translator 94 where it is converted into a destination address with VCI and YPI
components. It is then available for transmission on from connection 87.

In the event of a route fault occurring, this is detected by microprocessor 96 which instructs translator 91 to choose an alternative preferred route for switching.

Thus ATM cross-connects and ATM exchange equipment is configured to handle the addressing mech~ni~ms provided by the base stations and is compatible for Zonal operation. This means that the destination address is preserved from inlet to outlet of the switch and hence is preserved over the route from end-to-end. At the switch inlet 85 the VPI and VCI numbers are used to reference special routing tables within block 92 for Zonal packets and an internal routing label is created. This 9~

~abel has sufficient room to store the destination addres~ as wQ~l as containing information to route the ATH packet to the corr~ct outlet.

Afi ex~ ed~ the routing tables can take account o~ faUlt condi~ions by storing Ifirst preferred~ and ~second preferred' outle~ together with t~e ~ppropriate routing tags for internal switch operation. An automattc fault alarm would cause the routlng tables to switch to ~he ~econd pre~Qrred outlet if approprlate.
The routlng tables are the only resource which i~ ~p~cial to the mobile u~ers and the same ATN switches can be used for other B-ISDN ser~ce~, if required.

Although the sy~tem has been descr~bed in term~ of broadcast~ng information packets t~ all ad~acent base station8 to ensure mobile users can operate without cut-of~, ln an alternatl embodlmen~ a predictor mechanism can be employed ~o predict from the current and previous address inform~t~on the movement path of the user to restrict the number of ad~acent stations copied or ~roadcast, to reduce bandwidth require~ents.

Thus as shown in Figure 6, the router 40 could be configured a6 a ring mech~ m 100 with a number of nodQs 101-104 c;~ hle of hAndl~g packetised in~or~ation. Wlthln node 104 i8 a predictor block 10~ which Lncludes a store 107 for conn6~ion numbers and a Rtore 10~ for dQstln~tion addresses. Dependent on chan~es ln user location t~e predictor determines which ba~e s~ations are ~ppropriate to currently receivo the r~ ts dependent on the movement pa~tern and adds instrUction8 thereon to the packetised lnformation to allow this to pass round the ring to $nstr~ct the other nodQs ~01-103 whethe~ to accepk or dlscard packets received.

2 ~, h ~

Informa~on ~or use by the predictor 106 could be provlded within the ba~e ~tation interface units, see unit 13a for èxample. Cu~tomer identity informa~ion for ex~ple i5 avAil~h~l~ from blo~k ~3 and changes can be pa~sed vla the mic-~plocessor 61 for use ~y the predictor 106.

Although ~he system has been described generally a8 h~ndling packetified voice infor~ation (i.e. voice data), other packet lnformation (e.g. computer data) could be handled.

Claims

We Claim:

1. A mobile communications system including:
a plurality of base stations, routing means for connecting any base station to any other base station, a plurality of means each associated with one of said base stations, for packetising control signals and packetising data signals, and a plurality of means each associated with one of said base stations for tracking the current physical address within a packet switched network of a moving terminal to which control and/or data packets are to be passed and from which control and/or data packets are received.

2. A system as claimed in claim 1, wherein the tracking means associated with each station includes means for generating origination base station physical address information and destination base station physical address information to accompany user information, means for enabling any station to determine which route information therefrom is to take dependent on said destination information and means for updating location or destination information on a mobile user.

3. A system as claimed in claim 2 in which the user information is packetised, and in which the means for determining the information routes includes means for retaining remote user's base station address information, means for retaining local user's base station address information and means for generating packetised information thereon to accompany packetised user information.

4. A system as claimed in claim 3 wherein the retaining means includes means for retaining packetised information on adjacent base stations to enable a local user to change base station without loss of connection.

5. A system as claimed in claim 3 or 4 wherein remote user destination address generator means is configured to generate a first portion indicative of path identification and a second portion indicative of channel identification, for inclusion in a packet header.

6. A system as claimed in claim 5 wherein the path identification generator includes means for generating a near end broadcasting network address and the channel identification generator includes means for generating a near end connection number.

7. A system as claimed in any one of claims 2, 3 or 4 wherein the tracking means includes generator means for updating a remote base station with information on the customer identity of both customers communicating via the remote and local base stations.

8. A system as claimed in claim 7 including a controller and wherein the tracking means includes generator means for updating a remote base station with controller address information.

9. A system as claimed in claim 8 including means for generating packetised charging information to be sent to said controller.

10. A system as claimed in claim 7 including means for detecting updated information from a remote tracking means and means for responding to said updated information to generate updated information on a local associated terminal identified by the received updated information received from the remote tracking means.

11. A system as claimed in claim 6 including detector means for detecting that a moving terminal has moved to a new broadcast address and means for generating a new near end connection number whenever a broadcast address change has been detected.

12. A system as claimed in claim 11, including means for holding a set of free connection numbers for use by moving terminals and means for selecting a free connection number from a set of pre-assigned connection numbers.

13. A system as claimed in claim 9, including means for detecting that a terminal is no longer at a near end base station to initiate operation of the means for generating packetised charging information.

14. A system as claimed in claim 13, wherein counter means are provided to count packets and the count provided thereby is output whenever the detector means detects the terminal is no longer at the near end base station, said output being connectable to the means for generating packetised charging information to allow charging to be calculated.

15. A system as claimed in any one of claims 1-4 wherein the means for packetising control signals includes selector means for selecting one of a plurality of controllers at a remote location for receiving charging information and initial path selection.

16. A system as claimed in any one of claims 1-4 wherein the means for packetising control signals includes means for generating voice packets and means for inserting a connection number and destination base station information therein.

17. A system as claimed in any one of claims 1-4 wherein the routing means includes means for detecting address information accompanying packet information to route packets as determined by detected destination addresses.

18. A system as claimed in claim 17 wherein the means for detecting address information includes means for generating an internal routing signal to accompany the address information to ensure correct routing within the routing means.

19. A system as claimed in claim 18 wherein the means for generating a routing signal is configured to generate more than one routing signal to route the information in dependence on route availability.

20. A system as claimed in claim 19 including means for detecting fault conditions on a preferred route and means for selecting an alternative preferred route thereafter.

21. A system as claimed in one of claims 1-4 wherein the routing means comprise ATM switches configured to handle packetised information on an optical network.

22. A system as claimed in any one of claims 1-4 including interconnection means provided to connect a plurality of base stations to the routing means to allow a number of adjacent base stations to each receive incoming information therefrom.

23. A system as claimed in claim 22 wherein the interconnection means includes means for predicting movement patterns of users from address information to limit the number of adjacent base stations receiving identical information dependent on predicted user movements to reduce bandwidth requirements.

24. A system as claimed in claim 23 wherein the interconnection means includes detector means connected to a group of base stations to intercept information for transmission to one or more of the base stations dependent on accompanying control information provided by the predictor means.

25. A system as claimed in claim 22, 23 or 24 wherein the interconnection means includes a communications ring connecting a plurality of base station groups.

26. A method of controlling a mobile communications system having a plurality of base stations, the method comprising: providing a routing path for connecting any base station to any other base station, packetising control information at each station and packetising data information at each station and at each station tracking of the current physical address within a packet switched network of a moving terminal to which control and/or data packets are to be passed and from which control and/or data packets are received.

27. A method as claimed in claim 26, wherein the tracking step includes generating origination base station physical address and destination base station physical address information to accompany user information, determining which route information therefrom is to take dependent on said destination information and updating location or destination information on a mobile user.

28. A method as claimed in claim 27 wherein the route determining step includes retaining remote user's base station address information, retaining local user's base station address information and generating packetised information thereon to accompany packetised user information.

29. A method as claimed in claim 28 wherein the retaining step includes retaining packetised information on adjacent base stations to enable a local user to change base station without loss of connection.

30. A method as claimed in claim 28 wherein the destination address generation step includes generating a first portion indicative of path identification and generating a second portion indicative of channel identification, for inclusion in a packet header.

31. A method as claimed in claim 30 wherein the path identification generating step includes generating a near end broadcasting network address and the channel generation step includes generating a near end connection number.

32. A method as claimed in any one of claims 27 to 31 wherein the tracking step includes updating a remote base station with information on the customer identity of both customers communicating via the remote and local base stations.

33. A method as claimed in claim 32 including the steps of detecting updated information resulting from tracking at a remote station and responding to said information to generate updated information on a local associated terminal identified by the updated information received from the remote station.

34. A method as claimed in claim 31 including the steps of detecting that a moving terminal has moved to a new broadcast address and generating a new near end connection number whenever a broadcast address change has been detected.

35. A method as claimed in claim 34, including the steps of holding a set of free connection numbers for use by moving terminals and selecting a free connection number from a set of pre-assigned connection numbers.

36. A method as claimed in claim 34 or 35, including detecting that a terminal is no longer at a near end base station to initiate operation of a charging information generation step.

37. A method as claimed in claim 36, including counting packets and outputting the packet count whenever the detection step determines that the terminal is no longer at the near end base station to allow charging to be calculated.

38. A method as claimed in any one of claims 26, 31, 34 or 35 wherein the packetising control step includes generating voice packets and inserting a connection number and destination base station information therein.

39. A method as claimed in any one of claims 26, 31, 34 or 35 wherein the routing path step includes detecting address information accompanying packet information to route packets as determined by detected destination addresses.

40. A method as claimed in claim 39 wherein the address information detection step includes generating an internal routing signal to accompanying the address information to ensure selection of the correct routing path.

41. A method as claimed in claim 40 wherein the routing signal generation step is configured to generate more than one routing signal to route the information in dependence on route availability and fault detection is provided for detecting fault conditions on a preferred route to allowing selection of an alternative preferred route thereafter.

42. A method as claimed in any one of claims 26, 31, 34 or 35 wherein the routing path selection step is provided using Asynchronous Transfer Mode techniques to allow packetised information to be routed on an optical network.

43. A method as claimed in any one of claims 26, 31, 34 or 35 including interconnecting a plurality of base stations to the routing path to allow a number of adjacent base stations to each receive incoming information therefrom.

44. A method as claimed in claim 43 wherein the interconnecting step includes predicting movement patterns of the users from address information to limit the number of adjacent base stations receiving identical information dependent on predicted user movements to reduce bandwidth requirements.

45. A method as claimed in claim 44 wherein the interconnection step includes detecting at a group of interconnected base stations information for transmission to one or more of the base stations dependent on accompanying control information provided by the prediction step.