Title of Invention

A METHOD OF CONTROLLING RECEIPT OF SIGNALS AT A TERMINAL OF A COMMUNICATIONS SYSTEM

Abstract A method of controlling receipt of signals at a terminal (1) of a communications system comprises receiving data (Dl, D2) on at least one control channel from a first base station (2) . The terminal is adapted to periodically perform measurements on signals transmitted by at least one second base station (3, 4). The terminal determines whether a period in which data signals (D2) are on the at least one control channel at least partially overlaps with a period for performing measurements (M2) and disables performance of measurements in favour of receipt of data on the at least one control channel.
Full Text Description
The invention relates to a method of controlling receipt of signals at a terminal of a
communications system, in particular for a mobile radio communications system.
In radio communications system, signals are exchanged between radio terminals and
radio stations to base stations via a so called radio interface or air interface. Such
radio terminals are mobile or stationary user terminals or user equipments (UE). The
base stations or Node Bs are access stations that are associated with a land based
communication network. Examples of known radio communication systems are
second generation digital mobile radio communication systems such as global
system for mobile communication (GSM), based on time division multiple access
(TDMA) and providing data rates up to 100 kbit/s, or third generation digital mobile
radio communication systems such as universal mobile telecommunication system
(UMTS), based on code division multiple access (CDMA) with data rates up to 2
Mbit/s.
A new feature in current radio communication systems such as GSM, GSM edge
radio access network (GERAN) and UMTS, UMTS terrestrial radio access network
(UTRAN) is the provision of multimedia broadcast multicast service (MBMS). Radio
bearers for multicast MBMS services are set up within a cell of a base station, if there
are user equipments present in the cell with the particular MBMS service activated.
One of the main differences between MBMS and previous services is that MBMS can
be offered and used when the user equipment is an idle mode, i.e. without an
established radio connection to the network. The service uses a point-to-multipoint
connection, either in a multicast or broadcast mode. General principles of MBMS are
described in the standard documents 3GPP TR 25.992, V1.2.0 (2003-01) "Multimedia
Broadcast Multicast Service (MBMS); UTRAN/GERAN Requirements", TS 23.846,
V6.1.0 (2003-01) "MBMS; Architecture and functional description (Release 6)", TS
22.146, V6.6.0 (2004-10) "MBMS ; Stage 1 (Release 6)" and TS 45.002, V6.6.0
(2004-05) "Multiplexing and multiple access on the radio path (Release 6).
With the introduction of MBMS in UTRAN, a significant amount of control information
related to the MBMS configuration in the cell of a base station is provided on an
MBMS control channel (MCCH). A UE is required to periodically read this MCCH
based upon the provision of services in the cell for which the UE is registered. The
information scheduling and further parameters of the MCCH are described in detail in
the standard document 3GPP TS 25.346.V6.2.0 (2004-09), chapter 5.2.
However, existing UE behaviour specifies that a UE is required to periodically make
measurements of the neighbour cells in order for a UE to choose the cell in which it
should operate. These measurements require the UE to measure channels provided
in other cells, but a single receiver UE is unable to measure these channels and
listen in its own cells at the same time.
This problem is exacerbated if the period over which the MCCH is repeated is a
multiple of the frequency of occurrence of the occasions when the UE is required to
perform neighbour cell measurements.
Information provided on the MCCH is repeated over a period of time known as the
modification period, as defined in the above TS 25.346. This time interval defines the
period over which one static set of MCCH information is provided to the UE. Some
information used for notification purposes may change over this period, but this is not
significant. Information within a modification period is repeated a number of times,
each repetition being known as a repetition period. Each modification period is an
exact multiple of a repetition period.
At the start of each modification period an index is sent which contains information
about which services ongoing in the cell have had some configuration parameters
changed since the last modification period and which have remained the same. This
index is sent in order to reduce the amount of time the UE is required to read MCCH
each modification period. If the index is not correctly read, the UE must read the
whole of MCCH unti! it has successfully read all information.
Therefore, a method for efficiently establishing new connections in situations
described above is required.
Erissson : "Measurement requirements and MBMS reception', 3GPP TSG-RAN
WG4#32, R4-040437; 16.-20.08.2004; pages 1 to 11; XP002362097 describes the
existence of the problem of the conflict between inter-frequency and inter-RAT
measurement with MBMS decoding during MBMS sessions.
Siemens ; "Measurement requirements and MBMS reception in Cell-FACH state";
3GPP TSG RAN WG4#32, R4-040413; 18.20.08.2004; pages 1 to 5; XP002362098
describes a number of options for dealing with the impact of MBMS data loss on
MBMS quality of service.
In accordance with a first aspect of the present invention, a method of controlling
receipt of signals at a terminal of a communications system comprises receiving data
on at least one control channel from a first base station; wherein the at least one
control channel is associated with a multimedia broadcast multicast service (MBMS)
channel; wherein the terminal is adapted to periodically perform measurements on
signals transmitted by at least one second base station; wherein the terminal
determines whether a period in which data signals are on the at least one control
channel at least partially overlaps with a period for performing measurements; and, if
thete is an overlap, the terminal disables performance of measurements in favour of
receipt of data on the at least one control channel.
Conventionally, measurements of neighbour cells take absolute priority, however, the
present invention makes use of the fact that a sufficiently good quality set of
measurements can be obtained in fewer measurement periods than those specified,
so rather than delay a measurement when there is a conflict between receiving
control data and taking the measurements, as proposed in some prior art systems,
the present invention simply discards taking measurements in that particular
measurement period and uses only the measurements obtained in other periods,
whilst giving priority in the circumstances to receipt of control data in that period. This
improves overall efficiency of the system.
Preferably, the data on the at least one control channel is repeated periodically.
Preferably, the data on the at least one control channel relates to changes in the
configuration of the associated MBMS channel.
Preferably, performance of measurements is disabled until all data on the changes
has been received by the terminal.
In accordance with a second aspect of the present invention, a terminal for a
communication system comprises receiving means for receiving data on at least one
control channel from a first base station; wherein the at least one control channel is
associated with a multimedia broadcast multicast service (MBMS) channel;
measuring means for periodically performing measurements on signals transmitted
by at least one second base station; processing means for determining whether a
period in which data signals are on the at least one control channel at least partially
overlaps with a period for performing measurements, and, disabling means for
disabling performance of measurements in favour of the receipt of data on the at
least one control channel, if there is an overlap.
The terminal could be a static terminal, but preferably the terminal is a mobile
terminal.
In accordance with a third aspect of the present invention a communication system
comprises at least one base station and at least one terminal, for carrying out a
method according to the first aspect.
Preferably the at least one terminal is a mobile terminal according to the second
aspect.
An example of a method and apparatus according to the present invention will now
be described with reference to the accompanying drawings in which;
Figure 1 shows a block diagram of a radio communication network for the present
invention;
Figure 2 illustrates relative occurrence of control channel data and measurement time
periods for applying the method of the present invention.
Fig.1 shows a typical arrangement whereby a terminal 1 sends data to a base station
2 and receives signaling from the base station on the MBMS control channel
(MCCH). At various times, the terminal 1 must take measurements of neighbour cells
3 and 4.
As shown in Fig.2, there can be conflict if a time period in which data is being
transmitted on the MCCH overlaps or coincides with a time period in which a
measurement of the neighbour cells is to be made.
Initially, a data block D1 is transmitted and a measurement period M1 occurs after
this. Next, an index 12 is sent, followed by a the next data block D2. A second
measurements period M2 is allocated immediately followed by a third measurement
period M3. However, M3 overlaps with the next MCCH period, beginning with index
13. Therefore, the terminal 1 reads the index and if the index 13 indicates that there is
information of relevance to the terminal, then reading of D3 takes precedence over
the measurement of neighbour cells.
Thus, for any occasion when the UE detects that a measurement period and an
MCCH modification period boundary or repetition period occur at the same time, the
UE initially gives priority to reading the MCCH until the UE has successfully read the
index. If a UE has read the index for this modification period and this indicates that
there is nothing for the UE to read in this MCCH modification period, the UE
continues with the measurement periods as currently specified. If the UE reads the
index for this modification period, and the index indicates that there is information of
relevance to the UE, then the UE gives priority to reading the MCCH, rather than to
the coinciding measurement occasions until the UE has successfully read the MCCH
block which carries the relevant service information. Thereafter, the UE proceeds
with the measurement periods as specified.




We Claim:
1. A method of controlling receipt of signals at a terminal (1) of a communications
system comprising the following steps:
receiving of data on at least one control channel being associated with a multimedia broadcast multicast service (MBMS) channel from a first base station;
periodically performing the measurements at the terminal (1) on signals transmitted by at least one second base station (2);
determining at the terminal whether the period in which the data signals (D2, D3) are transmitted on the channel at least partially overlaps with a period in which the measurements are performed; and
disabling performance of the measurements in favour of receipt of the data signals (D2, D3) on the at least one control channel in the event of any overlap.
2. A method as claimed in claim 1, wherein the at least one control channel is associated with a multimedia broadcast multicast service (MBMS) channel.
3. A method as claimed in claim 1 or 2, wherein the data on the at least one control channel is repeated periodically.
4. A method as claimed in claim 2 and 3, wherein the data on the at least one control channel relates to changes in the configuration of the associated (MBMS) channel.

5. A method as claimed in claim 4, wherein performance of measurements is disabled until all data on the changes has been received by the terminal.
6. A communication system, comprising: a first base station to transmit data signals on
a control channel associated with a multimedia broadcast multicast service (MBMS) channel; a terminal (1) comprising a receiver to receive data signals on at least one control channel from the first base station, a measurement unit to periodically perform measurements (Ml, M2, M3) on signals transmitted by a second base station (2); and a processor configured to determine whether transmission of the data signals by the first base station overlaps with performance of the measurements, and to disable performance of the measurements in favor of receipt of the data signals under condition of any partial overlap.
7. A communications system as claimed in claim 6, wherein the data on the at least one
control channel is repeated periodically.

8. A communications system as claimed in claim 6, wherein performance of measurements is disabled until all data on the changes has been received by the terminal (1).

Documents:

2626-delnp-2007-abstract.pdf

2626-delnp-2007-assignment (24-03-2008).pdf

2626-DELNP-2007-Claims-(05-09-2011).pdf

2626-delnp-2007-claims.pdf

2626-delnp-2007-correspondece-others.pdf

2626-DELNP-2007-Correspondence Others-(05-09-2011).pdf

2626-delnp-2007-correspondence-others (23-05-2007).pdf

2626-delnp-2007-correspondence-others (24-03-2008).pdf

2626-delnp-2007-correspondence-others (28-04-2008).pdf

2626-delnp-2007-correspondence-others 1.pdf

2626-delnp-2007-description (complete).pdf

2626-delnp-2007-drawings.pdf

2626-delnp-2007-form-1 (23-05-2007).pdf

2626-delnp-2007-form-1 (24-03-2008).pdf

2626-delnp-2007-form-1.pdf

2626-delnp-2007-form-18.pdf

2626-delnp-2007-form-2.pdf

2626-delnp-2007-form-26.pdf

2626-DELNP-2007-Form-3-(05-09-2011).pdf

2626-delnp-2007-form-3.pdf

2626-delnp-2007-form-5 (24-03-2008).pdf

2626-delnp-2007-form-5.pdf

2626-delnp-2007-form-6 (24-03-2008).pdf

2626-delnp-2007-gpa (28-04-2008).pdf

2626-delnp-2007-pct-210.pdf

2626-delnp-2007-pct-409.pdf

2626-delnp-2007-pct-416.pdf

2626-DELNP-2007-Petition-137-(05-09-2011).pdf

abstract.jpg


Patent Number 257895
Indian Patent Application Number 2626/DELNP/2007
PG Journal Number 47/2013
Publication Date 22-Nov-2013
Grant Date 18-Nov-2013
Date of Filing 09-Apr-2007
Name of Patentee NOKIA SIEMENS NETWORKS GMBH & CO. KG,
Applicant Address ST. MARTIN STR. 76, 81541 MUNCHEN, GERMANY
Inventors:
# Inventor's Name Inventor's Address
1 PROCTOR, TOBY,KIER 30,ST.ANN STREET, SALISBURY HAMPSHIRE SP1 2DP GREAT BRITAIN
2 BREUER, VOLKER SCHWALBNRING 20,16727, BOTZOW, GERMANY
3 KROTH, NORBERT 30, ST.ANN STREET, SALISBURY HAMPSHIRE SP1 2DP, GREAT BRITAIN
4 RANDALL, DAVID 8, THE THICKET, ROMSEY, HAMPSHIRE S051 5SZ, GREAT BRITAIN
PCT International Classification Number H04L 12/18
PCT International Application Number PCT/GB2005/003884
PCT International Filing date 2005-10-10
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 0424806.8 2004-11-10 U.K.