Cellular Communications Equipment LLC v. Apple Inc. et al

Filing 1

COMPLAINT against AT&T Inc., AT&T Mobility LLC, Apple Inc., Boost Mobile, LLC, Cellco Partnership d/b/a Verizon Wireless, Sprint Corporation, Sprint Solutions, Inc., Sprint Spectrum L.P., T-Mobile US, Inc., T-Mobile USA, Inc., Verizon Communications, Inc. ( Filing fee $ 400 receipt number 0540-4484085.), filed by Cellular Communications Equipment LLC. (Attachments: # 1 Civil Cover Sheet, # 2 Exhibit A - U.S. Patent No. 6,377,804, # 3 Exhibit B - U.S. Patent No. 6,819,923, # 4 Exhibit C - U.S. Patent No. 7,215,962, # 5 Exhibit D - U.S. Patent No. 7,941,174, # 6 Exhibit E - U.S. Patent No. 8,055,820)(Ward, Thomas)

EXHIBIT A

111111

1111111111111111111111111111111111111111111111111111111111111
US006377804Bl

(54)

United States Patent

(10)

Lintulampi

(12)

(45)

5,920,818
5,960,354
5,995,610
5,995,842
6,002,931
5,960,365
6,047,177
6,081,708

MOBILE COMMUNICATION SYSTEMS

(75)

Inventor:

(73)

Assignee: Nokia Mobile Phones Ltd., Espoo (FI)

( *)

Notice:

Raino Lintulampi, Kiviniemi (FI)

This patent issued on a continued prosecution application filed under 37 CFR
1.53(d), and is subject to the twenty year
patent term provisions of 35 U.S.c.
154(a)(2).
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.c. 154(b) by 0 days.

(21)

Filed:

(30)

Jun. 11, 1998

Foreign Application Priority Data

Jun. 24, 1997

(51)
(52)
(58)

(FI) ................................................. 972722

Int. CI? .................................................. H04Q 7/20
U.S. CI. ....................... 455/435; 455/426; 455/552;
455/553; 455/432; 455/433
Field of Search ................................. 455/434, 435,
455/432, 458, 445, 450, 433, 553, 426,
552

(56)

References Cited
U.S. PATENT DOCUMENTS
5,410,732
5,563,393
5,613,213
5,724,648
5,839,075
5,901,352

A
A
A
A
A
A

*
*
*
*
*
*

4/1995
10/1996
3/1997
3/1998
11/1998
5/1999

A
A
A
A
A
A
A
A

*
*
*
*
*
*
*
*

7/1999
9/1999
11/1999
11/1999
12/1999
4/2000
4/2000
6/2000

Frogigh et al. .............
Einola ........................
Smidt et al. ................
Jonsson ......................
Yamaguchi et al. ........
Leih et al. ..................
Wickman ...................
Vasnier .......................

455/443
455/454
379/207
455/462
455/433
455/552
455/422
455/426

FOREIGN PATENT DOCUMENTS
GB

WO
WO
WO

2289191 A
WO 96/28947
WO 96/34503
WO 96/38992

11/1995
9/1996
* 10/1996
* 12/1996

H04Q/7/38

OTHER PUBLICATIONS
Finnish Office Action. *

Appl. No.: 09/095,906

(22)

Patent No.:
US 6,377,804 BI
Date of Patent:
*Apr. 23, 2002

Ames et al. ................ 455/422
La Porta et al. ........ 379/221.02
Nadell et al. ............... 455/414
Shaughnessy et al. ..... 455/56.1
Haartsen et al. ............ 455/450
St-Pierre et al. ............ 455/426

* cited by examiner
Primary Examiner-Daniel S. Hunter
Assistant Examiner-Yemane Woldetatios
(74) Attorney, Agent, or Firm-Perman & Green, LLP
ABSTRACT

(57)

A method of operating a mobile telephone within a geographical area having overlapping coverage from a first,
GSM, network and a second, UMTS, network, where said
GSM network is the home network (HPLMN) of the mobile
communication device and said GSM and UMTS networks
provide respective first and second sets of services in said
geographical area. The method comprises registering the
telephone with the GSM network when a service of said first
set is requested and registering the device with the UMTS
network when a service of said second set, but not of said
first set, is requested. The method provides the mobile
telephone with a roaming for service function.
14 Claims, 6 Drawing Sheets

2

3

u.s.

Patent

Apr. 23, 2002

US 6,377,804 BI

Sheet 1 of 6

3

FIG.1
//////~~~
I

/

------- -----

------------- ----------

----""""

\

\/

\

I

I

,

\
\

\

'\
\

4

5
I

,,

,

.....

""-

'-

-- ---

-------- -'
----------------------

3

FIG.2

-';

~~

,.;"

'

/

/

I

I

}

u.s. Patent

Apr. 23, 2002

Sheet 2 of 6

NO

YES
HPLMN
SELECTED

SERVICE
RELEASE

SERVICE
ATTEMPT
VPLMN
NO
SELECTED

FIG.3

US 6,377,804 BI

SELECT NEXT
PLMN IN THE LIST

d

IGSM-RAN:I

I

l UMTS-RAN: I

IGSM-op:GSM-CNI

IUMTS-op:GSM-CN J

[B-user-network

IdleMode

I

I

BEARER ASSIGNMENT

•
rJl
•
~

~
.....
.....
~

=
>

set-up-request(QoS)

't:I

:"l

measurement report

N

~

~

I
2

RESOURCE ANALYSIS

N
C
C
N

I

A-HORequired
MAP-prepare-HO(UMTSCeIIID)

'JJ.

=-

~

~

A-HORequest

~

3

A-HOCommand

A-HOAck

A-HOdetect
MAP-process-access-sig
channellnfo

HOCommand

o
....,

e
rJ'l

MAP-prepare-HO-resp

0'1

IceliChangel
HOaccess

0'1
~

HOComplete

4
._----

---------------

""-l
""-l

FIG.4a

L-- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

00
Q

---------------

1....-.----

~

~

I--"

----- --------------- ----------------- ----------------r---------------- r---------------A-HOComolete

MAP-send-end-~ig

~

~
.....
.....
~

A-clr-command

"

=

CONNECTED

I

5

SET-UP

\.

set-up-request(QoS)
set-up-completed
I

>

't:I

:"l

I startServiceBilling I

6

N

~~

I

"
I

7

"\

END-TO-END-COMMUNICATION

"-

RELEASE
I

I

8 celiReselection

~

I

N
C
C
N

'JJ.

=-

I stopServiceBilling I

IdleMode

d

•
rJl
•

~
~

.....

~

I

I

BILLING

I

o
....,
0'1

syslnfo(MCC, NCC,ceIlID)
I
_._-_.- - -

FIG.4b

FIG.4

FIG.4a
FIG.4b

e
rJ'l
0'1

~
""-l
""-l

00
Q

~

~

I--"

d

•
rJl
•

FIG.50

'"1"

IGSM BSS

/

I

I GSM SGSN

I

I GSM GGSN:

I

I UMTS RAN:

I IUMTS

SGSN:

I

IUMTS GGS
SN:

.....
.....
~

=

STANDBY/READY

....

~

~

SENDER(se~sion.sender _Tspec)

1

I

RESOURCE ANALYSIS

~

J

:"l
N

UPCALL(session.~esv_error)

2

~~

MM-RA-update
SGSN context req uest
GTP-SGSN contex request
GTP-SGSN context response
Cancel location

3

Cancel location ack

N
C
C
N

'JJ.

=-

~
~

.....
SGSN context rE sponse

Ul

o
....,
0'1

MM-RA-updateAccepted
/
\.

READY
SENDER(session,sender_Tspec)

4

I

I

RESOURCE ANALYSIS

e
rJ'l
0'1

~

pc these

----

L..- _ _

~

__________________

-------------

----------~-

------------ ------------

--.

""-l
",""-l
00
Q

~

~

I--"

d

~-----

--------- -------------

-------------- ------------ ------------ ------------

5
UPCALL(sessio

1.- -

•
rJl
•

confirm)

~

~

.....
.....
~

6

START ROAMING
READY TIMER

I

=

startServiceBit
'\

APPLICATION DATA TRANSFER

>

't:I

:"l
N

ROAMING READY
TIMER EXPIRES
RELEASE(session)
7

~~

N
C
C
N

resvTe
STANDBY

"

I

I

MM-RA-update

I

I

I

inter GGSN RA update

STANDBY

....

'JJ.

=-

~
~

.....

0'1

I

8

stopServiceBill

I

I

o
....,
0'1

I

BILLING

I
FIG.5b

FIG.5

FIG.50
FIG.5b

e
rJ'l
0'1

~
""-l
""-l

00
Q

~

~

I-"

US 6,377,804 Bl
1

2

MOBILE COMMUNICATION SYSTEMS

a geographical area having overlapping coverage from first
and second mobile telephone networks, where said first
FIELD OF THE INVENTION
network is the home network of the mobile communication
The present invention relates to mobile communication
device and said first and second networks provide respective
systems and more particularly to a method of operating a 5 first and second sets of services in said geographical area,
mobile communication device within a geographical area
the method comprising registering the device with said first
having overlapping coverage from first and second mobile
network when a service of said first set is requested and
telephone networks, where said first network is the home
registering the device with said second network when a
network of the mobile communication device and said first
service of said second set, but not of said first set, is
and second networks provide respective first and second sets
requested.
of services. The present invention also relates to a system for 10
Typically, although not essentially, the overall geographiperforming this method of operation.
cal coverage of said second network is less than that of said
first network, as is likely to be the case in the period
BACKGROUND OF THE INVENTION
following the introduction of a new mobile telephone stanA number of digital mobile telephone standards are in use
dard which is implemented by said second network.
throughout the world. These include the European GSM
Preferably, a service provided by said second network, but
standard and the US TDMA standard. However, due to the 15
not by said first network, is a high transmission rate service,
ever increasing demand for mobile telephone services many,
that is at a higher transmission rate than is possible with
if not all of these standards are likely to be superseded by
services provided by said first network. Examples of high bit
new standards offering increased network capacity and/or
rate services are internet browsing, videophone, and data
increased data transmission rates. In particular, the European
Telecommunications Standards Institute (ETSI) is currently 20 downloading.
The request for a service may be made by the mobile
developing a so called third generation mobile environment
communication device, e.g. in response to a user input, or by
known as the Universal Mobile Telecommunication System
the first network, e.g. in response to an incoming call made
(UMTS) which it is expected will be operational by 2002.
to the mobile communication device. In either case, in the
UMTS will operate in the 2 GHz frequency band and will
offer data transmission rates of up to 2 Mbits/sec, compared 25 event that a service of said second set, but not of said first
set, is requested, registration with said second network may
to a rate of only 9.6 Kbits/sec offered by the existing GSM
be carried out automatically under the control of said first
standard.
network. In this event, there is no need for the user of the
In the transition from second generation standards to third
mobile communication device to be aware of the change of
generation standards, there is likely to be a period when both
second and third generation standards will have to coexist. 30 registration. Alternatively, a decision on a change of registration may be made by a user via a user interface of the
It is also possible that such coexisting networks will be
mobile communication device.
operated by different operators. As with all previous
In one embodiment of the present invention, said first
standards, networks implementing the new standards are
network is a GSM network and said second network is a
likely to be introduced piece-meal, extending their geographical coverage over time. It may also be the case that the 35 UMTS network and said mobile communication device is a
dual mode UMTS/GSM device.
geographical coverage offered by third generation networks
According to a second aspect of the present invention
will always be less than that offered by second generation
there is provided a mobile telecommunication system comnetworks due to the need to sustain high bit rate transmisprising at least first and second mobile telephone networks
sions with the former.
having an overlapping geographical area of coverage and a
It is proposed (in Europe at least) to enable mobile 40 multiplicity of mobile communication devices, wherein said
stations registered with a third generation network as the
first network is the home network of the mobile communi"home" network (i.e. the network to which the mobile
cation devices and said first and second networks are
stations subscribe) to transfer to a second generation netarranged to provide respective first and second sets of
work when the stations are outside the coverage area of the
telephonic services in said geographical area, the system
home network, with appropriate cross-billing agreements 45 comprising control means for registering a communication
between the network operators, to alleviate the possible
device with said first network when a service of said first set
is requested and for registering the device with said second
geographical limitations. This transfer will operate in subnetwork when a service of said second set, but not of said
stantially the same way as the "roaming" function of confirst set, is requested.
ventional GSM networks (GSM 03.22) where a station can
register with an alternative network when the RF connection 50
The control means may comprise means associated with
each of the mobile communication devices for transmitting
between the mobile station and the home network is too
a deregistration request to the first network and for transweak to support a traffic channel. Of course third generation
mitting a registration request to the second network when a
terminals will have to be dual mode, e.g. UMTS/GSM, in
service of said second set, but not of said first set, is
order to take advantage of this facility.
The inventors of the present invention have addressed the 55 requested. Alternatively, the control means may comprise
means associated with the first network for responding to a
problem of how mobile stations registered with earlier
request from a communication device for a service of said
generation networks, e.g. second generation networks, as
second set, but not of said first set, by re-registering the
their home network may gain access to new services only
communication device with the second network.
available through new generation networks, e.g. third generation networks. This may be a requirement of reciprocal 60
The mobile communication devices may be, for example,
mobile telephones, combined mobile telephone/personal
arrangements between second and third generation network
digital assistant devices, or other devices which use wireless
operators. As far as the inventors are aware this problem has
telephonic communication.
not been previously addressed.
SUMMARY OF THE INVENTION
According to the present invention there is provided a
method of operating a mobile communication device within

65

BRIEF DESCRIPTION OF THE INVENTION
For a better understanding of the present invention and in
order to show how the same may be carried into effect

US 6,377,804 Bl

3

4

reference will now be made, by way of example, to the
location registration are not necessarily required because the
accompanying drawings, in which:
MS 3 can remain registered with the home GSM network
which knows the location of the MS 3.
FIG. 1 shows schematically the geographically coverage
area of example second and third generation mobile teleFIGS. 4A and 4B illustrate a possible implementation
5 scenario for the roaming for service unction where data
phone networks;
transmission between the MS 3 and the networks is by
FIG. 2 shows in block diagram form the architectures of
circuit switched transmission (i.e. where one or more traffic
the second and third generation networks of FIG. 1;
channels are reserved for the duration of the transmission).
FIG. 3 shows a flow diagram of the operation of a mobile
The following legends are used in FIGS. 4A and 4B:
station in the coverage area of the networks of FIG. 1;
FIGS. 4A and 4B show at the signaling level an imple- 10
mentation of the method of FIG. 3 for circuit switched
transmission; and
MS
Mobile Station
FIGS. 5A and 5B show at the signaling level an impleRadio Access Network
RAN
Core Network
CN
mentation of the method of FIG. 3 for packet switched
GSM-op
GSM operator, owner of the first network
transmission.
15
UMTS-op

UMTS operator, owner of the second network

DETAILED DESCRIPTION
As already noted above, in Europe, UMTS networks are
The following table contains a description of the meslikely to be introduced with only limited geographical
sages of FIGS. 4A and 4B:
coverage. This situation is illustrated in FIG. 1 where the 20
coverage 1 provided by the UMTS network falls within the
coverage area 2 of a pre-existing GSM network. When a
A-HORequired
indication from the radio access network that
UMTS compatible mobile station (MS) 3, which has the
hand over is needed
UMTS network as its home network (or home public land
MAP-prepare-HO
hand over request between networks
mobile network HPLMN), is located within the UMTS 25 A-HORequest
hand over request to the radio access network
A-HOAck
acceptance of hand over request from the radio
network coverage area 1, the MS 3 is registered with the
access network
UMTS network and is able to make use of all the services
MAP-prepare-HO-resp
response to handover request between networks
provided by that network (or at least those services to which
A-HOCommand
hand over command to the radio access network
the MS user has subscribed). Providing that the MS is also
HOCommand
hand over command to the MS
MS sends access attempt to the radio access
GSM compatible, and that an appropriate agreement exists 30 HOAccess
network
between the operators of the UMTS and GSM networks,
A-HOdetect
the radio access network informs network that
when the MS detects that it has moved outside of the UMTS
the MS's access attempt has been detected
network coverage area 1 it is able to register with the GSM
MAP-process-accessindication that handover process is ongoing
sig
network (as a visiting public land mobile network VPLMN)
the radio access network informs the MS that
and to make use of the services provided by the GSM 35 HOComplete
handover process has been completed
network. The services provided by the GSM network are
the radio access network informs network that
A-HOComplete
likely to be more limited than those provided by the UMTS
handover process has been completed
MAP-send-end-sig
the second network informs the first network
network but this disadvantage is more than offset by the
that handover process has been completed
increased coverage area available to the UMTS network
A-elr-command
the first network commands the radio access
subscriber. This arrangement is similar in principle to the 40
network to release reserved radio resources
'roaming for coverage' function available with current GSM
MSs, e.g. which operates when a MS moves from one
Signaling can be divided into eight main steps as follows:
country to another, as defined in GSM specification 03.22.
1. The MS sends a service request with quality of service
The architectures of the GSM and UMTS networks are
(QoS) parameters to the GSM network. These QoS
shown schematically in FIG. 2 where the dual-mode GSMI- 45
parameters may include bit transmission rate, bit error
UMTS MS 3 communicates with either the UMTS BSS
rate, and transmission delay.
(base station subsystem) 4 and the GSM/GPRS (global
2. The GSM network analyses the available resources for
packet radio service) core network 5 or with the GSM/DCS
the service. The GSM network detects that it cannot
BSS 6 and the GSM/GPRS core network 7. The two core
provide the requested quality of service thus it sends a
networks 5,7 cooperate according to a roaming agreement 50
handover request to the UMTS network.
between the two network operators.
3. The UMTS network accepts the handover request. The
Consider now the case where the MS 3 is registered with
MS is commanded to the UMTS network with hanthe GSM network as its HPLMN. The MS 3 may make use
dover command and the MS makes an access attempt
of the GSM services throughout the GSM coverage area 2,
after the MS has changed to the UMTS network's cell.
including the UMTS coverage area 1 because of the over- 55
4. Handover access has been detected by the UMTS
lapping coverage which exists there. However, if the MS 3
network and the resources of the GSM network are
requires to use of a service provided by a UMTS network
released.
(i.e. as a VPLMN) but not by the GSM network, the MS 3
5. The MS continues the service request signaling with the
must 'roam' for that service. This is different from the
UMTS network.
conventional 'roaming for coverage' offered by GSM and is 60
6. The UMTS network starts billing procedure in order to
not defined in GSM specification 03.22. FIG. 3 is a flow
bill the GSM network for the service.
diagram of the roaming for service operation illustrating that
the HPLMN will be selected by the MS 3 so long as that
7. When the service is released the billing procedure is
network is available and the selected service is provided by
stopped.
the HPLMN.
65
8. The MS selects the GSM network if it is available.
Roaming for service differs from traditional roaming for
FIGS. 5A and 5B illustrate a possible implementation
coverage in that, with the former, location updates and thus
scenario for the roaming for service function where data

US 6,377,804 Bl
5

6

transmISSIOn between the MS 3 and the networks is by
packet switched transmission (i.e. where transmission time
slots are dynamically allocated for transmission according to
demand and priority). The following legends are used in
FIGS. 5A and 5B:

be handed over to the UMTS network. In this way, the
operation can be transparent to the user who is unaware that
a handover has occurred in an alternative approach however,
the MS may be configured such that it is able to determine
when a requested service is not provided by the GSM
network. The MS may then automatically, or following a
prompt from the user, de-register with the GSM network and
subsequently register with the UMTS network.
It will be appreciated by those of skill in the art that
further modifications may be made to the above described
embodiments without departing from the scope of the
present invention. For example, the invention may be used
to provide service roaming between any two or more networks which provide different numbers or levels of service,
e.g. two GSM or two UMTS networks.

MS
BSS
SGSN
GPRS
GGSN
RAN
IP

Mobile Station
Base Station Subsystem
Service GPRS Support Node
General Packet Radio Service
Gateway GPRS Support Node
Radio Access Network
Destination Internet Protocol Node

5

10

15

The following table contains a description of the messages of FIGS. 5A and 5B:
Glossary

SENDER(session,
sender_Tspec)
UPCALL(session,
resv _error)
MM-RA-update
SGSN context request
GTP-SGSN context
request
GTP-SGSN context
response
Cancel location
Cancel location ack
SGSN context
response
MM-RAupdateAccepted
path(sender,
sender_Tspec)
rsvp(Tspec)
UPCALL(session,
resv_confirm)
RELEASE(session)
resvTear(session)

application session in the MS requests quality of
service described in sender_Tspec
error message with code "quality of service
cannot be provided"
routing area update message
context for the MS is requested
context request between two GGSNs

20

25

context request confirmation
location cancelled from the previous SGSN
location cancellation acknowledgment
the MS context activation accepted by GGSN

35

session release
resource release between IP nodes
40

Again, signaling can be divided into eight main steps as
follows:
1. Application in the MS sends a service request with
quality of service parameter to the GSM network.
2. Available radio resources are analysed and a service
request is rejected due to the lack of resources. The MS
selects the UMTS network.
3. The GSM and the UMTS network exchange information about the MS and finally the UMTS network
accepts the MS to access the network.
4. Application in the MS sends a service request with
quality of service parameter to the UMTS network.
5. The UMTS network has radio resources available and
it sends path-message to the destination IP node.
Resources for the session are found and the MS is
confirmed about the resource reservations.
6. Data transfer between application starts. Billing and
roaming starts.
7. Application is closed or timer expires. The session is
closed and resource reservations are released.
8. The MS selects the GSM network. The UMTS network
bills the GSM network for the service.
In the implementations of FIGS. 4Aand 4B and FIGS. 5A
and 5B, it is the GSM network which determines, from the
request made by the MS, whether or not it can provide the
requested service and therefore whether or not the MS must

Base Station Subsystem
Digital Cellular System (at 1800 MHz)
Digital European Cordless Telecommunications
Home Location Register
Home Public Land Mobile Network
Internet Engineering Task Force
International Mobile Subscriber Identity
Internet Protocol
General Packet Radio Service
Global System for Mobile Communications
Mobile Station
Reservation Set-up Protocol
Universal Mobile Telecommunications System

30

routing area updating confirmation
quality of service request to the destination IP
node
merged quality of service request to the previous
IP node
connection and quality of service confirmation

BSS
DCS
DECT
HLR
HPLMN
IETF
IMSI
IP
GPRS
GSM
MS
RSVP
UMTS

45

50

55

60

65

What is claimed is:
1. A method of operating a mobile communication device
within a geographical area having overlapping coverage
from first and second mobile telephone networks, where said
first network is the home network of the mobile communication device and said first and second networks provide
respective first and second sets of services in said geographical area, the method comprising registering the device with
said first network when a service of said first set is requested
and registering the device with said second network when a
service of said second set, but not of said first set, is
requested.
2. A method according to claim 1, wherein the overall
geographical coverage of said second network is less than
that of said first network.
3. A method according to claim 1, wherein the request for
a service is made by the mobile communication device in
response to a user input.
4. A method according to claim 1, wherein the request for
a service is made by the first network in response to an
incoming call made to the mobile communication device.
5. A method according to claim 3, wherein, in the event
that a service of said second set, but not of said first set, is
requested, registration with said second network is carried
out automatically under the control of said first network.
6. A method according to claim 1, wherein said first
network is a GSM network and said second network is a
UMTS network and said mobile communication device is a
dual mode UMTS/GSM device.
7. The method according to claim 1 wherein the requested
service of the second set is not a service of the set of services
of said first set.
8. A method according to claim 1, wherein said choosing
a desired service is independent of the availability of the
service in the first network.
9. A method according to claim 1, wherein a serVIce
provided by said second network, but not by said first
network, is a high transmission rate service.

US 6,377,804 Bl
7

8

10. A mobile telecommunication system comprising at
13. A mobile telecommunication system comprising at
least first and second mobile telephone networks having an
least first and second mobile telephone networks having an
overlapping geographical area of coverage and a multiplicity
overlapping geographical area of coverage and a multiplicity
of mobile communication devices, wherein said first netof mobile communication devices, whereni said first network is the home network of the mobile communication 5 work is the home network of the mobile communication
devices and said first and second networks are arranged to
devices and said first and second networks are arranged to
p~ovid~ resI;ective first and second sets of telephonic serprovide respective first and second sets of telephonic serVIces III saId geographical area, the system comprising
vices in said geographical area, the system comprising:
control means for registering a communication device with
control means for registering a communication device with
said first network when a service of said first set is requested
said first network when a service of said first set is requested 10
and for registering the device with said second network
and for registering the device with said second network
when a service of said second set, but not of said first set, is
when a service of said second set, but not of said first set, is
requested, wherein the control means comprises means
requested, wherein the control means comprises means for
associated with each of the mobile communication devices
determining if the desired service belongs to said first set, in
for transmitting a deregistration request to the first network
response to a request for service received from said mobile 15
and for transmitting a registration request to the second
communications device.
network when a service of said second set, but not of said
11. A system according to claim 10, wherein the control
first set, is requested.
means comprises means associated with the first network for
14. A system according to claim 13, wherein the control
responding to a request from a communication device for a
means comprises, means associated with each of the mobile
service of said second set, but not of said first set, by 20
communication devices for transmitting a de registration
re-registering the communication device with the second
request to the first network and for transmitting a registration
network.
request to the second network when a service of said second
12. The system according to claim 10 wherein the
set, but not of said first set, is requested.
requested service of the second set is not a service of the set
of services of said first set.
* * * * *