Cellular telecommunications network

Abstract

This invention provides a method of operating an access point in a cellular telecommunications network, the cellular telecommunications network further comprising a User Equipment, UE, wherein the access point operates according to a cellular telecommunications protocol defining a mandatory System Information Block, SIB, SIB1, and a plurality of further SIB, SIB2 to SIBn, the method comprising the steps of: transmitting a SIB1 message to the UE during a System Frame Number, SFN, superframe, the SIB1 message indicating, for each SIB of one of SIB2 to SIBn, a broadcast parameter of each SIB message of a set of SIB messages for one of SIB2 to SIBn such that the set of SIB messages for one of SIB2 to SIBn are transmitted periodically for less than an entirety of the SFN superframe; and transmitting, to the UE, each SIB message of the set of SIB messages for one of SIB2 to SIBn according to its respective broadcast parameter.

Description

[0001] B36006

[0002] CELLULAR TELECOMMUNICATIONS NETWORK

[0003] Field of the Invention

[0004] The present invention relates to a cellular telecommunications network.

[0005] 5

[0006] Background

[0007] In a cellular telecommunications network, an access point broadcasts various control messages known as “information block” messages. One or more of these information block messages are deemed essential, such as the Master Information Block (MIB) and System Information Block (SIB) type 1 (SIB1), as they include information that must be decoded by a User Equipment (UE) in order for that UE to attach to the access point and access the cellular telecommunications network via the access point. The access point may also broadcast one or more non-essential SIBs, such as SIB type 2 (SIB2) to SIB type 9 (SIB9). The information included in the non-essential SIBs is not required for the 15 UE to attach to the access point, but instead comprises further information such as mobility configuration settings.

[0008] SIB1 may define one or more broadcast parameters for the non-essential SIB. The broadcast parameters include a broadcast status of a particular non-essential SIB 20 indicating whether or not a particular non-essential SIB is being broadcast. The broadcast parameters also include a periodicity of a particular non-essential SIB indicating a time interval between periodic broadcasts of that non-essential SIB.

[0009] The access point may reduce resource (e.g. processing and / or spectrum) consumption 25 by setting the broadcast status of a non-essential SIB so that the non-essential SIB is no longer being broadcast. However, an access point restart is required to switch the broadcast status back so that the non-essential SIB is being broadcast again. Restarting the access point is undesirable as no communications between the access point and the UE being served by the access point occur during the restart and all UE must re-attach to the access point following the restart. The restart may be requested by a UE that requires information contained in a non-essential SIB, but this request is only possible if the UE is in CONNECTED (rather than IDLE or INACTIVE) mode.

[0010] It is desirable to alleviate some or all of the above problems. B36006

[0011] Summary of the Invention

[0012] According to a first aspect of the invention, there is provided a method of operating an access point in a cellular telecommunications network, the cellular telecommunications network further comprising a User Equipment, UE, wherein the access point operates 5 according to a cellular telecommunications protocol defining a mandatory System Information Block, SIB, SIB1, and a plurality of further SIB, SIB2 to SIBn, the method comprising the steps of: transmitting a SIB1 message to the UE during a System Frame Number, SFN, superframe, the SIB1 message indicating, for each SIB of one of SIB2 to SIBn, a broadcast parameter of each SIB message of a set of SIB messages for one of SIB2 to SIBn such that the set of SIB messages for one of SIB2 to SIBn are transmitted periodically for less than an entirety of the SFN superframe; and transmitting, to the UE, each SIB message of the set of SIB messages for one of SIB2 to SIBn according to its respective broadcast parameter.

[0013] 15 According to a second aspect of the invention, there is provided a method of operating a User Equipment, UE, in a cellular telecommunications network, the cellular telecommunications network further comprising an access point, wherein the UE operates according to a cellular telecommunications protocol defining a mandatory System Information Block, SIB, SIB1, and a plurality of further SIB, SIB2 to SIBn, the 20 method comprising the steps of: receiving, from the access point, a SIB1 message during a System Frame Number, SFN, superframe, the SIB1 message indicating, for each SIB of one of SIB2 to SIBn, a broadcast parameter of each SIB message of a set of SIB messages for one of SIB2 to SIBn such that the set of SIB messages for one of SIB2 to SIBn are transmitted periodically for less than an entirety of the SFN superframe; and 25 receiving, from the access point, each SIB message of the set of SIB messages for one of SIB2 to SIBn according to its respective broadcast parameter.

[0014] The plurality of further SIBs, SIB2 to SIBn, may be non-essential SIBs, in which n is an integer greater than 2.

[0015] The broadcast parameter may comprise a time of broadcast of each SIB message of a set of SIB messages for one of SIB2 to SIBn, and the time of broadcast may be defined by: a time of broadcast of a first SIB message of the set of SIB messages for one of SIB2 to SIBn. B36006

[0016] The time of broadcast of each SIB message of a set of SIB messages for one of SIB2 to SIBn may be further defined by: a count of further SIB messages of the set of SIB messages for one of SIB2 to SIBn, and a period between each SIB message of the set of SIB messages for one of SIB2 to SIBn.

[0017] 5

[0018] The SIB1 message may further comprise a new information indication indicating whether the next SIB message of a set of SIB messages for one of SIB2 to SIBn comprises new information relative to a previous SIB message of that set of SIB messages.

[0019] The respective broadcast parameter of each SIB message of the set of SIB messages for a first SIB of one of SIB2 to SIBn may differ from the respective broadcast parameter of each SIB message of the set of SIB messages for a second SIB of one of SIB2 to SIBn.

[0020] 15 According to a third aspect of the invention, there is provided a computer program comprising instructions which, when the program is executed by an access point, cause the access point to carry out the steps of the method of the first aspect of the invention.

[0021] According to a fourth aspect of the invention, there is provided a computer program 20 comprising instructions which, when the program is executed by a User Equipment, UE, cause the UE to carry out the steps of the method of the second aspect of the invention.

[0022] The computer program of the third or fourth aspects may be stored on a computer readable carrier medium, which may be non-transitory.

[0023] According to a fifth aspect of the invention, there is provided an access point comprising a processor configured to carry out the steps of the method of the first aspect of the invention.

[0024] 30 According to a sixth aspect of the invention, there is provided a User Equipment, UE, comprising a processor configured to carry out the steps of the method of the second aspect of the invention. B36006

[0025] Brief Description of the Figures

[0026] In order that the present invention may be better understood, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings in which:

[0027] 5

[0028] Figure 1 is a schematic diagram of a cellular telecommunications network;

[0029] Figure 2 is a transmission timing diagram illustrating transmissions by the access point of the network of Figure 1 ;

[0030] Figure 3 is a flow diagram illustrating a method of operating an access point of the network of Figure 1 ;

[0031] Figure 4 is a flow diagram illustrating a method of operating a user equipment of the network of Figure 1 ; and

[0032] Figure 5 is a transmission timing diagram illustrating transmissions by the access point implementing the method of Figure 3.

[0033] 15

[0034] Detailed Description

[0035] Figure 1 illustrates a cellular telecommunications network 100. The cellular telecommunications network 100 comprises an access point 110 and a User Equipment (UE) 120. The access point 110 and UE 120 are configured to communicate using a 20 cellular telecommunications protocol, such as the 3rdGeneration Partnership Project (3GPP) family of 4thGeneration (4G) standards and / or 5thGeneration (5G) standards. The access point 110 is therefore configured to transmit a plurality of information blocks, such as a Master Information Block (MIB) and a plurality of System Information Blocks (SIBs), including SIB type 1 (SIB1), and SIB type 2 (SIB2), etc. The MIB and SIB1 are 25 deemed essential as the information included in the MIB and SIB1 must be decoded by the UE 120 in order for the UE 120 to attach to the access point 110 and access the cellular telecommunications network 100 via the access point 110. One or more other SIBs, such as SIB type 2 (SIB2), are deemed non-essential as the information included in the one or more other SIBs are not required for the UE to attach to the access point. Hereinafter, any non-essential SIB is referred to as SIBn, being distinguished from the essential SIB1.

[0036] Figure 2 illustrates a transmission timing diagram using System Frame Number (SFN) time units. Transmissions in the cellular telecommunications network 100 are divided

[0037]

[0038] B36006

[0039] duration of 10ms. The SFN is a common time reference for all nodes in the cellular telecommunications network and is a count of frames from 0 to 1023 in 4G and 0 to 65535 in 5G. When the SFN reaches its maximum value, a new SFN frame (known as a “superframe” in 4G and a “hyperframe” in 5G) starts with the SFN value restarting at 5 0. The current SFN is transmitted as part of the MIB message in 5G and as part of the SIB1 message in 4G. The current SFN indicates the SFN at the time of transmission of the MIB orSIBI message.

[0040] The MIB and SIB1 are periodically transmitted according to a fixed periodicity, being every 4 frames starting from SFNO for the MIB and every 8 frames starting from SFNO for SIB1. Further redundancy copies of the MIB and SIB1 are transmitted in between the respective periodic transmissions. All non-essential SIBs (not shown in Figure 2) are transmitted according to the broadcast parameters defined in SIB1.

[0041] 15 SIB1 defines a plurality of broadcast parameters, known as Scheduling Information, for each non-essential SIB, including:

[0042] • Broadcast Status: indicating whether or not a particular non-essential SIB is being broadcast, with possible values “notBroadcasting” if the particular non- essential SIB is not being broadcast, and “broadcasting” if the particular non- 20 essential SIB is being broadcast; and

[0043] • Periodicity: indicating a time interval being periodic broadcasts of a particular non-essential SIB, with possible values 8, 16, 32, 64, 128, 256 and 512 (in frames).

[0044] The Scheduling Information also includes further broadcast parameters, for each non- essential SIB, including:

[0045] • Time Reference: indicating a start time (in SFN) of a first SIB message of a set of SIB messages for the non-essential SIB in the current SFN superframe. The Time Reference value may be empty if no messages of a particular non-essential 30 SIB are being transmitted in the current SFN superframe; and

[0046] • Repetitions: indicating a count of repetitions of the SIB message in the set of SIB messages for the non-essential SIB, with possible integer values from (and including) 0 to (and including) 31. B36006

[0047] A method of operating an access point 110 is illustrated in Figure 3. In a first step, S101, the access point 110 configures broadcast parameters for each non-essential SIB for the current SFN superframe. The broadcast parameters for a particular non-essential SIB are specific to that non-essential SIB for the current SFN superframe and may be the 5 same as or differ from the broadcast parameters for any other non-essential SIB.

[0048] The broadcast parameters define the broadcast timing of each non-essential SIB message in the current SFN superframe, including the time of broadcast (in SFN) in the current SFN superframe of the first SIB message of a set of SIB messages for a particular non-essential SIB and, if applicable, the time of broadcast in the current SFN superframe of zero, one or more further SIB messages of the set of SIB messages for that particular non-essential SIB. That is, the Time Reference value indicates, for a particular non- essential SIB, the broadcast time (in SFN) in the current SFN superframe of the first SIB message of a set of SIB messages for that non-essential SIB. For example, by 15 configuring the Time Reference value for SIB2 as SFN10, then the access point 110 is configured to broadcast the first SIB2 message in the current SFN superframe at SFN 10. Furthermore, the Periodicity and Repetitions values indicate, for a particular non- essential SIB, the broadcast time (in SFN) in the current SFN superframe of zero, one or more further SIB messages of a set of SIB messages for that non-essential SIB. For 20 example, by configuring the Periodicity value as 64 and the Repetitions value as 2, then the access point 110 is configured to broadcast the second SIB2 message (i.e. the first repetition of the SIB2 message of a total of 2 repetitions) at SFN74 (64 frames after the first SIB2 message), and to broadcast the third SIB2 message (i.e. the second repetition of the SIB2 message of a total of 2 repetitions) at SFN 138 (64 frames after the second SIB2 message).

[0049] In step S103, the access point 110 prepares the MIB message, SIB1 message, and each non-essential SIB to be broadcast by the access point 110. The SIB1 message is prepared by setting the Scheduling Information so as to define the broadcast parameters 30 for each non-essential SIB for the current SFN superframe, as configured in step S101.

[0050] That is, the SIB1 message is prepared so as to indicate, for each non-essential SIB, the broadcast time (in SFN) in the current SFN superframe of a first SIB message of a set of SIB messages for that non-essential SIB (by the Time Reference value) and the broadcast time (in SFN) in the current SFN superframe of zero, one or more SIB B36006

[0051] messages of the set of SIB messages for that non-essential SIB (by the Periodicity and Repetitions values).

[0052] In step S105, the access point 110 broadcasts the MIB, SIB1 and non-essential SIB(s) 5 messages according to their respective broadcast parameters.

[0053] A method of operating the UE 120 is illustrated in Figure 4. The UE 120 is operating in IDLE or INACTIVE mode and monitors information block broadcasts from the access point 110. In a first step, S201, the UE 120 receives a SIB1 message from the access point 110.

[0054] In step S203, the UE 120 determines the broadcast timing of each SIB message of the set of SIB messages for each non-essential SIB in the current SFN superframe based on the broadcast parameters of each non-essential SIB indicated in the received SIB1 15 message.

[0055] In step S205, the UE 120 is configured to receive each SIB message of each set of SIB messages of each non-essential SIB in the current SFN superframe based on the current SFN (as indicated in the received SIB1 message) and the broadcast timing (as 20 determined in step S203).

[0056] Figure 5 illustrates an example of a transmission timing diagram of an access point 110 implementing the method of Figure 3. The transmission timing diagram covers portions of adjacent first, second and third SFN superframes. SIB1 messages are periodically 25 transmitted by the access point 110 at a fixed periodicity of 8 frames (i.e. SFN0, SFN8,

[0057] SFN16, etc. in the first, second and third SFN superframes). In this example, each SIB1 message of the first and second SFN superframes defines the same broadcast parameters for the SIB2 message, being:

[0058] • Periodicity: 64 frames,

[0059] • Time Reference = SFN 10, and

[0060] • Repetitions = 2.

[0061] Furthermore, in this example, each SIB1 message of the third SFN superframe defines the same broadcast parameters for the SIB2 message, being:

[0062] 35 • Periodicity: 64 frames, B36006

[0063] • Time Reference = empty, and

[0064] • Repetitions = empty.

[0065] Therefore, as shown in Figure 5, the access point 110 transmits a first SIB2 message at 5 SFN10 of the first SFN superframe, a second SIB2 message at SFN74 of the first SFN superframe (the first repetition of the SIB2 message, 64 frames after the first SIB2 message), and a third SIB2 message at SFN138 of the first SFN superframe (the second repetition of the SIB2 message, 64 frames after the second SIB2 message). No further SIB2 messages are transmitted during the first SFN superframe as the two repetitions of the SIB2 message in the first SFN superframe are complete.

[0066] As the broadcast parameters for the SIB2 message, as contained in the SIB1 messages for the first and second SFN superframes, are the same, then the transmission pattern of the SIB2 messages in the second SFN superframe is identical to the transmission 15 pattern of the SIB2 messages in the first SFN superframe. That is, SIB2 messages are transmitted at SFN 10, SFN74 and SFN 138 of the second SFN superframe. No further SIB2 messages are transmitted in the second SFN superframe after SFN138 of the second SFN superframe.

[0067] 20 In the third SFN superframe, the access point 110 does not transmit any SIB2 messages.

[0068] In this example, the UE 120 (implementing the method of Figure 4) receives a SIB1 message from the access point 110 at SFN40 in the first SFN superframe (this may be, for example, due to the UE 120 roaming into the access point’s coverage area such that 25 the SIB1 message at SFN40 is the first SIB1 message the UE 120 receives from the access point 110). In step S203, the UE 120 determines the broadcast timing of each SIB message of the set of SIB messages for each non-essential SIB in the first SFN superframe based on the broadcast parameters of each non-essential SIB in the received SIB1 message. The UE 120 therefore determines that the broadcast times of the SIB2 messages in the first SFN superframe are SFN10, SFN74 and SFN138.

[0069] In step S205, the UE 120 is configured to receive any subsequently broadcast SIB message of the set of SIB messages of each non-essential SIB of the current SFN superframe based on the current SFN (SFN40) and the broadcast timing of each SIB 35 message of the set of SIB messages of each non-essential SIB in the current SFN B36006

[0070] superframe (e.g. SFN10, SFN74 and SFN138 for SIB2). As the SIB2 message at SFN10 is in the past, the UE 120 is configured to receive the SIB2 messages at SFN74 and SFN138 only. The UE 120 is not configured to detect SIB2 messages at any other time during the first SFN superframe and therefore does not waste any resources attempting 5 to receive a further SIB2 message between SFN170 and the end of the first SFN superframe.

[0071] In a second example, the UE 120 (implementing the method of Figure 4) receives a SIB1 message from the access point 110 at SFN 144 in the second SFN superframe (this may be, for example, due to the UE 120 roaming into the access point’s coverage area such that the SIB1 message at SFN144 of the second SFN superframe is the first SIB1 message the UE 120 receives from the access point 110). In step S203 of this second example, the UE 120 determines the broadcast timing of each SIB message of the set of SIB messages for each non-essential SIB in the second SFN superframe based on 15 the broadcast parameters of each non-essential SIB in the received SIB1 message. The UE 110 therefore determines that the broadcast times of the SIB2 messages in the second SFN superframe are SFN10, SFN74 and SFN138.

[0072] In step S205, the UE 120 is configured to receive any subsequently broadcast SIB 20 message of the set of SIB messages of each non-essential SIB of the current SFN superframe based on the current SFN (SFN144) and the broadcast timing of each SIB message of the set of SIB messages of each non-essential SIB in the current SFN superframe (e.g. SFN10, SFN74 and SFN138 for SIB2). As all SIB2 messages of the current SFN superframe are in the past, then the UE 120 is not configured to receive any 25 SIB2 messages for the remainder of the second SFN superframe. The UE 120 therefore does not waste any resources attempting to receive SIB2 messages during the second SFN superframe.

[0073] In a third example, the UE 120 (implementing the method of Figure 4) receives a SIB1 message from the access point 110 at SFN0 in the third SFN superframe. In step S203 of this third example, the UE 120 determines the broadcast timing of each SIB message of the set of SIB messages for each non-essential SIB in the third SFN superframe based on the broadcast parameters of each non-essential SIB in the received SIB1 message. The UE 110 therefore determines that no SIB2 messages are broadcast during the third 35 SFN superframe. B36006

[0074] In step S205, the UE 120 is configured to receive any subsequently broadcast SIB message of the set of SIB messages of each non-essential SIB of the current SFN superframe based on the current SFN (SFNO) and the broadcast timing of each SIB 5 message of the set of SIB messages of each non-essential SIB in the current SFN superframe. As no SIB2 messages are being broadcast in the third SFN superframe, then the UE 120 is not configured to receive any SIB2 messages for the remainder of the third SFN superframe. The UE 120 therefore does not waste any resources attempting to receive SIB2 messages during the first SFN superframe.

[0075] The methods implemented by the access point 110 and UE 120 provide benefits over the conventional method of scheduling each non-essential SIB. In the conventional method, each non-essential SIB could only be configured to be broadcast or not broadcast, with any change to this scheduling parameter requiring a restart operation of 15 the access point (and therefore a loss of service for any connected UE). By implementing the methods of Figures 3 and 4, the access point 110 and UE 120 may define more tailored scheduling parameters for each non-essential SIB such that 1) each non- essential SIB may be broadcast or not broadcast without restarting the access point 110, and 2) each non-essential SIB may be broadcast for a portion of an SFN superframe 20 (that is, it does not need to be broadcast for the entirety of the SFN superframe). This reduces the amount of resources (e.g. processing and communication resources) used by the access point 110 for preparing and broadcasting the non-essential SIB messages, and reduces the amount of resources (e.g. processing and communication resources) used by the UE 120 for receiving and processing non-essential SIB messages.

[0076] 25

[0077] In an enhancement to the above methods, the Scheduling Information comprises a further broadcast parameter, Modified Information. The Modified Information parameter indicates if one or more information elements of the next SIB message of a set of SIB messages for a particular non-essential SIB has changed since the most recently broadcast SIB message of that non-essential SIB, with possible values TRUE if there is at least one differentiated information element and FALSE if there are no differentiated information elements. The benefits of this broadcast parameter will now be discussed.

[0078] The access point 110 is configured to determine (e.g. as part of step S101 in determining 35 the broadcast parameters for each non-essential SIB), whether any information element B36006

[0079] of that non-essential SIB has changed since the most recently broadcast SIB message of that non-essential SIB). The access point 110 then prepares the SIB1 message, in step S103, to set the value for Modified Information as either TRUE (if there is at least one differentiated information element) or FALSE (if there are no differentiated 5 information elements). Following the example shown in Figure 5, the access point 110 broadcasts:

[0080] • SIB1 messages at SFNs 0 and 8 of the first SFN superframe having value Modified Information = TRUE for SIB2 (indicating that the SIB2 message at SFN 10 has at least one differentiated information element relative to the most recent SIB2 message broadcast in the previous SFN superframe),

[0081] • SIB1 messages at SFNs 16, 24, 32, 40, 48, 56, 64, and 72 of the first SFN superframe having value Modified Information = FALSE for SIB2 (indicating that the SIB2 message at SFN74 of the first SFN superframe does not have any differentiated information elements relative to the SIB2 message at SFN10 of the 15 first SFN superframe), and

[0082] • SIB1 messages at SFNs 80, 88, 96, 104, 112, 120, 128, and 136 of the first SFN superframe having Modified Information = TRUE for SIB2 (indicating that the SIB2 message at SFN138 of the first SFN superframe has at least one differentiated information element relative to the SIB2 message at SFN74 of the 20 first SFN superframe).

[0083] Following this example, the UE 120 receives a SIB1 message from the access point 110 at either SFN0 or SFN8 of the first SFN superframe. As noted above, the SIB1 message at SFN0 has value Modified Information = TRUE for SIB2, indicating that the next SIB message of the set of SIB messages for SIB2 (i.e. the SIB2 message at SFN10) contains at least differentiated information element relative to the previously broadcast SIB2 message. The UE 120 responds to this Modified Information value by being configured to decode the next SIB2 message at SFN10.

[0084] 30 Subsequently, the UE 120 receives a SIB1 message from the access point 110 at SFNs 16, 24, 32, 40, 48, 56, 64, and 72, each having value Modified Information = FALSE for SIB2, indicating that the next SIB2 message of the set of SIB messages for SIB2 (i.e. the SIB2 message at SFN74) does not contain any differentiated information element relative to the previously broadcast SIB2 message at SFN10. The UE 120 responds to B36006

[0085] this Modified Information value by not being configured to decode the next SIB2 message at SFN74.

[0086] Subsequently, the UE 120 receives a SIB1 message from the access point 110 at SFNs 5 80, 88, 96, 104, 112, 120, 128, and 136, each having value Modified Information = TRUE for SIB2, indicating that the next SIB message of the set of SIB messages for SIB2 (i.e. the SIB2 message at SFN138) contains at least one differentiated information element relative to the previously broadcast SIB2 message at SFN74. The UE 120 responds to this Modified Information value by being configured to decode the next SIB2 message at SFN138.

[0087] The Modified Information parameter therefore enables the UE 120 to selectively decode SIB messages of a particular non-essential SIB such that the UE 120 is only configured to decode the SIB messages of that non-essential SIB comprising new or modified 15 information relative to the most recently broadcast SIB message of that non-essential SIB. In other words, if the information between adjacent SIB messages of a particular non-essential SIB is the same, then the UE 120 may not be configured to decode the latter SIB message. A UE may therefore not decode that SIB message (and therefore save resources) if it has already decoded the most recently broadcast SIB message of 20 that non-essential SIB, or continue to decode that SIB message if it has not decoded the most recently broadcast SIB message for that non-essential SIB.

[0088] The skilled person will understand that the Modified Information parameter may indicate whether or not the SIB message contains a differentiated information element relative to 25 a different SIB (other than the most recently broadcast SIB message of that non-essential SIB). For example, the Modified Information parameter may indicate that the SIB message contains at least one differentiated information element relative to a SIB message of a previous SFN superframe (e.g. the most recently broadcast SIB message of that non-essential SIB in the previous SFN superframe).

[0089] The skilled person will understand that the Time Reference and / or Repetition fields (in combination with the Periodicity field) effectively defines the timing of the last (if any) SIB message of a particular non-essential SIB in a particular SFN superframe. That is, in contrast to the conventional method of transmitting a SIB message for each non- 35 essential SIB periodically for the entirety of the SFN superframe, the access point is B36006

[0090] configured to transmit (based on the Time Reference and Repetition values) zero, one or more SIB messages of a particular non-essential SIB for less than an entirety of the SFN superframe. In other words, the set of SIB messages for the SIB of one or more of SIB2 to SIBn are transmitted periodically for a first period of the SFN superframe and are 5 not transmitted for a second period of the SFN superframe, the second period being longer than a periodicity of the set of SIB messages.

[0091] The skilled person will also understand that the broadcast parameters for each non- essential SIB may be updated at any time during an SFN superframe. In this scenario, 10 any SIB1 message broadcast after the update would indicate the updated broadcast parameters and any UE receiving the SIB1 message would be reconfigured to receive and decode the non-essential SIB messages according to the updated broadcast parameters.

[0092] The skilled person will understand that any combination of features is possible within the scope of the invention, as claimed.

[0093] 20

Claims

B36006CLAIMS1. A method of operating an access point in a cellular telecommunications network, the cellular telecommunications network further comprising a User Equipment, 5 UE, wherein the access point operates according to a cellular telecommunications protocol defining a mandatory System Information Block, SIB, SIB1, and a plurality of further SIB, SIB2 to SIBn, the method comprising the steps of:transmitting a SIB1 message to the UE during a System Frame Number, SFN, superframe, the SIB1 message indicating, for each SIB of one of SIB2 to SIBn, a broadcast parameter of each SIB message of a set of SIB messages for one of SIB2 to SIBn such that the set of SIB messages for one of SIB2 to SIBn are transmitted periodically for less than an entirety of the SFN superframe; andtransmitting, to the UE, each SIB message of the set of SIB messages for one of SIB2 to SIBn according to its respective broadcast parameter.

152. A method of operating a User Equipment, UE, in a cellular telecommunications network, the cellular telecommunications network further comprising an access point, wherein the UE operates according to a cellular telecommunications protocol defining a mandatory System Information Block, SIB, SIB1, and a plurality of further SIB, SIB2 to 20 SIBn, the method comprising the steps of:receiving, from the access point, a SIB1 message during a System Frame Number, SFN, superframe, the SIB1 message indicating, for each SIB of one of SIB2 to SIBn, a broadcast parameter of each SIB message of a set of SIB messages for one of SIB2 to SIBn such that the set of SIB messages for one of SIB2 to SIBn are transmitted periodically for less than an entirety of the SFN superframe; and receiving, from the access point, each SIB message of the set of SIB messages for one of SIB2 to SIBn according to its respective broadcast parameter.

3. A method as claimed in either Claim 1 or Claim 2, wherein the broadcast 30 parameter comprises a time of broadcast of each SIB message of a set of SIB messages for one of SIB2 to SIBn, and the time of broadcast is defined by:a time of broadcast of a first SIB message of the set of SIB messages for one of SIB2 to SIBn.B360064. A method as claimed in Claim 3, wherein the time of broadcast of each SIB message of a set of SIB messages for one of SIB2 to SIBn is further defined by:a count of further SIB messages of the set of SIB messages for one of SIB2 to SIBn, and5 a period between each SIB message of the set of SIB messages for one of SIB2 to SIBn.

5. A method as claimed in any one of the preceding claims, wherein the SIB1 message further comprises a new information indication indicating whether the next SIB message of a set of SIB messages for one of SIB2 to SIBn comprises new information relative to a previous SIB message of that set of SIB messages.

6. A method as claimed in any one of the preceding claims, wherein the respective broadcast parameter of each SIB message of the set of SIB messages for a first SIB of 15 one of SIB2 to SIBn differs from the respective broadcast parameter of each SIB message of the set of SIB messages for a second SIB of one of SIB2 to SIBn.

7. A computer program comprising instructions which, when the program is executed by an access point, cause the access point to carry out the steps of any one of 20 Claims 1 and 3 to 6 when dependent on Claim 1.

8. A computer program comprising instructions which, when the program is executed by a User Equipment, UE, cause the UE to carry out the steps of any one of Claims 2 and 3 to 6 when dependent on Claim 2.

259. A computer readable carrier medium comprising the computer program of either Claim 7 or Claim 8.

10. An access point comprising a processor configured to carry out the steps of any one of Claims 1 and 3 to 6 when dependent on Claim 1.

11. A User Equipment, UE, comprising a processor configured to carry out the steps of any one of Claims 2 and 3 to 6 when dependent on Claim 2.35

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