WO2016198847A1

WO2016198847A1 - Broadcast service following using lookup table

Info

Publication number: WO2016198847A1
Application number: PCT/GB2016/051677
Authority: WO
Inventors: Hugh Griffiths
Original assignee: Imagination Technologies Limited
Priority date: 2015-06-08
Filing date: 2016-06-07
Publication date: 2016-12-15
Also published as: EP3304776A1; GB2539200B; GB2539200A; GB201509902D0

Abstract

A digital broadcast receiver for implementing service following using locally saved service following information. The digital broadcast receiver includes an interface configured to receive service following information from a user; a storage module configured to store the received service following information; a digital broadcast receiver module configured to receive a digital broadcast signal; a signal quality detection unit configured to monitor the quality of the received digital broadcast signal; and a processor configured to, in response to the signal quality detection unit detecting the quality of the received digital broadcast signal is below an acceptable level, select an alternate broadcast signal to receive based on the stored service following information.

Description

BROADCAST SERVICE FOLLOWING USING LOOKUP TABLE

Background

[0001] When a user is listening to a radio broadcast signal when they are travelling (e.g. while driving in a car or travelling by train) they may move out of range of the radio broadcast signal so that they can no longer listen to the selected radio broadcast signal. The user then typically has to perform a manual search of currently available radio stations to determine which one has similar content. This can prove quite time consuming and frustrating particularly when the user has moved to an area where they are not familiar with the local radio stations. Accordingly, the loss of a radio station generally causes a significant disruption to the user's listening experience and can be quite frustrating for the user.

[0002] To address this problem the concept of service following has been developed.

Service following is defined as maintaining the same audio or data content the user has selected in spite of varying reception conditions that occur, for example, when travelling by car or train. Accordingly, service following allows a user to continue to receive the same or similar audio or data content via another radio broadcast signal even after the user has travelled out of range of the radio broadcast signal they originally selected. Service following is typically accomplished by the radio receiver detecting when the quality of the radio broadcast signal the user is currently listening to falls below a predetermined threshold (e.g. the user has moved out of range); and, automatically selecting an available radio broadcast signal that provides identical or similar audio or data content to the radio broadcast signal the user is currently listening to.

[0003] The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known systems for implementing radio service following.

Summary

[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0005] Described herein are methods and digital broadcast receivers for implementing service following using locally saved service following information. The digital broadcast receiver includes an interface configured to receive service following information from a user; a storage module configured to store the received service following information; a digital broadcast receiver module configured to receive a digital broadcast signal; a signal quality detection unit configured to monitor the quality of the received digital broadcast signal; and a processor configured to, in response to the signal quality detection unit detecting the quality of the received digital broadcast signal is below an acceptable level, select an alternate broadcast signal to receive based on the stored service following information.

[0006] A first aspect provides a digital broadcast receiver comprising: an interface configured to receive service following information from a user; a storage module configured to store the received service following information; a digital broadcast receiver module configured to receive a digital broadcast signal; a signal quality detection unit configured to monitor the quality of the received digital broadcast signal; and a processor configured to, in response to the signal quality detection unit detecting the quality of the received digital broadcast signal is below an acceptable level, select an alternate broadcast signal to receive based on the stored service following information.

[0007] A second aspect provides a method of implementing service following using a digital broadcast receiver, the method comprising: receiving at the digital broadcast receiver service following information from a user; storing the received service following information at the digital broadcast receiver; receiving a digital broadcast signal at the digital broadcast receiver; monitoring the quality of the received digital broadcast signal; and in response to detecting the quality of the received digital broadcast signal is below an acceptable level, selecting an alternate broadcast signal to receive based on the stored service following information.

[0008] The methods described herein may be performed by a computer configured with software in machine readable form stored on a tangible storage medium e.g. in the form of a computer program comprising computer readable program code for configuring a computer to perform the constituent portions of described methods or in the form of a computer program comprising computer program code means adapted to perform all the steps of any of the methods described herein when the program is run on a computer and where the computer program may be embodied on a computer readable storage medium. Examples of tangible (or non-transitory) storage media include disks, thumb drives, memory cards etc. and do not include propagated signals. The software can be suitable for execution on a parallel processor or a serial processor such that the method steps may be carried out in any suitable order, or simultaneously.

[0009] The hardware components described herein may be generated by a non-transitory computer readable storage medium having encoded thereon computer readable program code.

[0010] This acknowledges that firmware and software can be separately used and valuable. It is intended to encompass software, which runs on or controls "dumb" or standard hardware, to carry out the desired functions. It is also intended to encompass software which

"describes" or defines the configuration of hardware, such as HDL (hardware description language) software, as is used for designing silicon chips, or for configuring universal programmable chips, to carry out desired functions.

[0011] The preferred features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the invention.

Brief Description of the Drawings

[0012] Embodiments of the invention will be described, by way of example, with reference to the following drawings, in which:

[0013] FIG. 1 is a flowchart of a method of implementing service following according to the DAB standard;

[0014] FIG. 2 is a schematic diagram of an example system for implementing service following using service following information locally stored on a DAB receiver;

[0015] FIG. 3 is a block diagram of the DAB receiver of FIG. 2;

[0016] FIG. 4 is a schematic diagram illustrating methods of transferring the service following information to the DAB receiver of FIG. 2;

[0017] FIG. 5 is a schematic diagram of the service following information of FIG. 2; and

[0018] FIG. 6 is a flowchart of an example service following procedure which may be executed by the DAB receiver of FIG. 2.

[0019] Common reference numerals are used throughout the figures to indicate similar features.

Detailed Description

[0020] Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved. The description sets forth the functions of the example and the sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples. [0021] As described above, broadcast service following allows an end-user to continue to receive the same or similar audio or data content to the broadcast service they have selected even after they are no longer able to receive (e.g. have lost) the originally selected broadcast service.

[0022] Digital Audio Broadcasting (DAB) is a digital radio standard that has been adopted by more than twenty countries including the United Kingdom and Australia. A DAB broadcast channel supports a multiplex of services known as an ensemble. The services can include primary services, such as main radio stations; secondary services, such as sports commentaries; and/or, data services such as an electronic programme guide (EPG), broadcast web sites, slideshows which may be synchronized with audio broadcasts, java platform applications, IP (Internet Protocol) tunneling, video, other raw data etc. Each ensemble is identified by an ensemble identifier (Eld) and each service within a DAB ensemble is identified by a service identifier (Sid).

[0023] The user or listener finds a programme by selecting a service, for example, BBC Radio 1 (BBC R 1) or BBC Radio Two (BBC R 2). A service may carry a variety of programmes. For example, "BBC Radio One" carries a plurality of programmes including "The Breakfast Show".

[0024] The DAB standard provides for service following by outlining information that may be provided by DAB service providers to allow DAB receivers to implement service following. Specifically, the DAB standard provides that service providers may provide the following three types of information to allow service following: service linking information, other ensembles service information and frequency information.

[0025] "Service linking information" allows a service provider to provide one or more sets of identifiers that identify services that carry (a) identical content (i.e. a hard-linked service); or (b) related content (i.e. a soft-linked service) for a particular service. Each set of identifiers is referred to as a linkage set. A linkage set typically includes Slds of other DAB services, but it also may include identifiers for services transmitted using other bearers, such as FM

(Frequency Modulation) with RDS (Radio Data System), DRM (Digital Radio Mondial) and AM (Amplitude Modulation) with AMSS (Amplitude Modulation Signaling System). Linking information for each bearer is transmitted using a separate service linking field. For example, if a service provider has services with identical content on two DAB services and three FM services the service provider transmits a first service linking information field with Id 1 and Id2 indicating the Slds of the two DAB services, and transmits a second service linking field with Id 1 , Id2 and Id3 indicating the PI (Program Identification) codes of the three FM (with RDS) services. [0026] "Other ensembles service information" is a list of geographically adjacent alternative ensembles on which the current service (and other services) may be found. "Frequency information" is information that indicates a list of alternative frequencies on which the current ensemble (and other ensembles) may be found.

[0027] These three types of information (service linking information, other ensembles information and frequency information) will be referred to herein as service following information. Specifically, service following information comprises one or more of service linking information, other ensembles information, and frequency information as described herein.

[0028] The rules for implementing DAB service following are set out in ETSI TS 103 176 V1.1 .2 (2013-07) herein incorporated by reference. According to these rules, once a DAB receiver has determined that the received signal for a selected service has dropped below a predetermined level the DAB receiver implements a three-stage process to implement service following. In the first stage, the DAB receiver attempts to recover the exact same service (i.e. a service with the same service ID (Sid)). In the second stage, the DAB receiver attempts to connect to a hard-linked service. In the third stage, the DAB receiver attempts to connect to a soft-linked service.

[0029] This three stage process 100 is illustrated in FIG. 1. Specifically, as shown in FIG. 1 , upon detecting that the radio broadcast signal for the selected service has dropped below a predetermined level the DAB receiver implements the first stage 102 of the process 100 where the DAB receiver attempts to locate and connect to another radio broadcast signal providing the exact same service (i.e. a service with the same service ID (Sid)) to that selected by the user. If the DAB receiver is able to locate a radio broadcast signal providing the exact same service to that selected by the user then the DAB receiver connects to that radio broadcast signal.

[0030] If, however, the DAB receiver is unable to locate and/or connect to a radio broadcast signal that provides the exact same service to that selected by the user then the DAB receiver implements the second stage 104 of the process 100 where the DAB receiver analyzes the service following information broadcast by the signal service provider(s) to attempt to locate and connect to a radio broadcast signal providing a hard-linked service. As described above a hard-linked service is one which has a different service ID than the selected service but provides identical audio and/or data content. The same content may be distributed in different ensembles with different Slds because on some ensembles the audio is coded as MPEG layer 2 and on other ensembles the audio is coded as ACC. If the DAB receiver is able to locate a radio broadcast signal that offers identical content then the DAB receiver connects to that radio broadcast signal.

[0031] If, however, the DAB receiver is unable to locate and/or connect to a radio broadcast signal that provides identical content to that selected by the user then the DAB receiver implements the third stage 106 of the process 100 where the DAB receiver analyzes the service following information broadcast by the radio broadcast signal service provider(s) to locate and connect to a radio broadcast signal providing a soft-linked service. As described above a soft-linked service is one which offers similar, but not identical, content to the selected service. If the DAB receiver is able to locate a radio broadcast signal that offers similar content then the DAB receiver connects to that radio broadcast signal.

[0032] If, however, the DAB receiver is unable to locate and/or connect to a radio broadcast signal that provides similar content then the user must manually selected a new service and/or radio broadcast signal.

[0033] Accordingly, the second and third stages 104 and 106 of the standard DAB service following rely on the service providers broadcasting service following information, however, there are jurisdictions, such as the United Kingdom, where the service following information may not be broadcast by the service providers because, for example, it is not supported by the current infrastructure. Accordingly in these jurisdictions, users may only be able to enjoy the first stage of DAB service following - i.e. they may only be automatically transferred to another DAB signal that uses the identical Sid. Therefore in these jurisdictions, when a user moves out of range of a DAB signal providing a selected service and there is not another DAB signal providing the same service with the same Sid they will be abruptly cut off from the audio or data content they are currently listening to/using and must manually select a new radio broadcast signal to connect to.

[0034] For example, a user in Reading listening to Heart Berkshire (Sld=C361) driving to Oxford would not automatically be transferred to Heart Oxford (Sld=C661) because although the two DAB signals provide the same service (e.g. same content) they do not use the same Sid. Similarly, a driver in Reading listing to Smooth Berkshire (Sld=CDD2) driving to Swindon would not automatically be transferred to Smooth Wiltshire (Sld=C1 D3).

[0035] Accordingly, the embodiments described herein relate to methods and digital broadcast receivers for implementing service following without using broadcast service linking information. In particular, in the embodiments described herein service following information is stored locally on the digital broadcast receiver and is used to implement service following. In some cases the service following information is provided to the digital broadcast receiver and/or updated on the digital broadcast receiver via an internet-enabled portable device, such as a mobile phone. In other cases the service following information may be manually provided to the digital broadcast receiver and/or updated on the digital broadcast receiver by the user.

[0036] Using locally stored service following information enables all stages of service following to be implemented to provide users with uninterrupted listening throughout a user's travels. It also allows modification of the service following information which can be customized for the user or by the user. In particular, it allows for linking between services that would otherwise not be available under the standard (e.g. linking of services that are not explicitly soft-linked or hard-linked).

[0037] The methods and digital broadcasts receivers will be described below using examples that implement service following for DAB signals, however the methods and systems described herein may equally be applied to other digital broadcast signals such as other digital radio broadcast signals (e.g. Digital Radio Mondiale (DRM); HD-Radio and Frequency Modulation (FM) radio with Radio Data System (RDS)) and digital television broadcast signals (e.g. mobile TV such as Terrestrial Digital Multimedia Broadcasting - Terrestrial (T-DMB), Digital Video Broadcasting - Handheld (DVB-H) and Digital Multimedia Broadcasting (DMB)).

[0038] Reference is now made to FIG. 2 which illustrates a system 200 for implementing service following using locally stored service following information. The system 200 comprises one or more DAB broadcast stations 202, 204 which each broadcast a DAB signal 206, 208. The system 200 also comprises a portable DAB receiver 210 for receiving DAB signals 206, 208 broadcast by the DAB broadcast stations 202, 204 and implementing service following based on locally stored service following information 211.

[0039] In particular, the service following information 211 links DAB services to equivalent (hard-linked) or related (soft-linked) services. In some cases the service following information 211 may be implemented as a lookup table that allows the DAB receiver 210 to easily identify hard and soft linked services for a particular service. Exemplary service following information 211 that may be stored by the DAB receiver 210 is described with reference to FIG. 5.

[0040] When the DAB receiver 210 detects that the quality of the selected signal (e.g. DAB signal 206) is below a predetermined threshold (e.g. when the DAB receiver 210 moves from a first region 212 to a second region 214) and it is unable to locate an alternate DAB signal with the exact same service ID it uses the stored service following information 211 to automatically select another radio broadcast signal to connect to (e.g. DAB signal 208). In some cases, the DAB receiver 210 may be configured to select alternative services in accordance with the DAB service following standard. In particular, in these cases the DAB receiver 210 may be configured to use the stored service following information 211 to attempt to find a hard-linked service and if no hard-linked service is found to find a soft-linked service.

[0041] The portable DAB receiver 210 may be any portable computing device capable of receiving DAB signals, such as a car radio, mobile phone, or portable radio. An example DAB receiver 210 will be described with reference to FIG. 3.

[0042] Reference is now made to FIG. 3 which illustrates an exemplary DAB receiver 210 of FIG. 2. The exemplary DAB receiver 210 comprises a DAB radio receiver 302 for receiving DAB signals; a tuner 304 for configuring the DAB radio receiver 302 to receive a specific DAB signal; an input module 305 for receiving a radio broadcast selection from the user; a signal quality detection unit 306 for monitoring the signal strength of the received DAB signal; a storage module 308 for storing the service following information 211 and a service following procedure 310 for implementing service following using the stored service following information 211 ; and a processor 309 for controlling the operation of the DAB radio receiver 302, tuner 304, and storage module 308; and executing and accessing the service following procedure 310 and the service following information 21 1 respectively.

[0043] The DAB radio receiver 302 is configured to receive DAB signals (e.g. DAB signals 206 and 208) broadcast by DAB broadcast stations (e.g. DAB broadcast stations 202 and 204). The DAB radio receiver 302 typically receives control information from the tuner 304 which tells it which DAB radio broadcast signal to receive (or attempt to receive). The user may control the tuner 304 by providing information identifying a desired service via the input module 305. The information identifying the service may include an Sid, Eld and a frequency. The frequency is then provided to the tuner 304 which sets or tunes the DAB radio receiver 302 to the desired frequency. The input module 305 may be any suitable device for receiving input from a user, such as, but not limited to, a mouse, keyboard, keypad, touch screen, or a traditional radio dial.

[0044] The DAB radio receiver 302 then applies the appropriate codec to retrieve the desired service from the received DAB ensemble signal. Where the service is an audio service the DAB radio receiver 302 provides the audio to the processor 309. The processor 309 then provides the audio to an audio output module 31 1. The audio output module 311 then outputs the audio in an audible manner so that the user can hear the audio. The audio output module 31 1 may, for example, be a speaker, headphone or another other suitable device that allows a user to hear audio.

[0045] The signal quality detection unit 306 monitors the DAB signal received by the DAB radio receiver 302 to track the quality of the received signal. If the signal quality detection unit 306 detects that the received DAB signal has fallen below an acceptable level then the signal quality detection unit 306 may notify the processor 309. The signal quality detection unit 306 may use any suitable measurement, such as signal strength, carrier to noise ratio (CNR), signal to noise ratio (SNR), symbol error rate (SER), bit-error rate (BER) etc., for assessing the quality of the received DAB signal. The signal quality detection unit 306 may determine that the received DAB signal has fallen below an acceptable level if the quality of the signal has fallen below a predetermined threshold. The predetermined threshold may be fixed or may be adjustable by the user.

[0046] Upon receiving an indication from the signal quality detection unit 306 that the quality of the received DAB signal has fallen below an acceptable level the processor 309 (in accordance with the service following procedure 310) initiates service following using the stored service following information 211. Service following may be implemented in several phases and the phase that is initiated upon receipt of an indication from the signal quality detection unit 306 that the quality of the received signal has fallen below an acceptable level may be based on the current status of the DAB receiver 210.

[0047] For example, in some cases when the user has manually selected a service to listen to, the DAB receiver 210 may be set to a status of "user selected service" and information indicating the selected service may be stored in the storage module 308. If the processor 309 subsequently receives an indication from the signal quality detection unit 306 that the quality of the received signal has fallen below an acceptable level the status of the DAB receiver 210 may be changed to "service following phase one". During phase one, the processor 309 attempts to locate an alternate DAB signal providing a service with the same Sid as the user selected service. The processor 309 may attempt to locate an alternate DAB signal providing the exact same service (i.e. has the same service ID as the selected service) by controlling the tuner 304 so as to continually adjust the frequency of the DAB radio receiver 302 until the signal quality detection unit 306 detects that the received DAB signal is of an acceptable level.

[0048] Since adjusting the frequency of the DAB radio receiver 302 to locate alternate signals may disrupt the audio etc. provided to the user, in some cases the DAB receiver 210 may comprise a second DAB radio receiver, and tuner (not shown) which are used for locating suitable alternative signals. In these examples, the second radio receiver may be connected to the same signal quality detection unit 306 as the first DAB radio receiver or a second signal quality detection unit (not shown)

[0049] Once the received DAB signal (from the DAB radio receiver or second DAB radio receiver) is of an acceptable level the processor 309 analyzes the signal to determine the one or more service IDs (Slds) associated with the signal. If one of the Slds of the received signal matches the Sid of the user selected service then the signal is sent to the audio output module 31 1.

[0050] If, however, the Sid of the received signal does not match the Sid of the user selected service then the processor 309 may be configured to continue through the frequencies until either a Sid match is found or all of the frequencies have been analyzed. In accordance with the DAB service following standard the processor 309 may be configured to prioritize frequencies that transmit the same ensemble as the user selected service.

[0051] If the processor 309 is unable to locate an alternate DAB signal providing a service with the same Sid as the user selected service in phase one then the status of the DAB receiver may be changed to "service following phase two". During phase two, the processor 309 attempts to locate a radio broadcast signal providing a service hard-linked to the service selected by the user based on the locally stored service following information 211. In particular, the processor 309 determines if the service following information 211 specifies any hard-linked services for the user-selected service. As described above, a hard-linked service is one that provides the same service as the user selected service using a different Sid. A hard-linked service may be a DAB service or a service on another bearer.

[0052] If the service following information identifies at least one hard-linked DAB service for the user-selected service then the processor 309 tunes the DAB radio receiver to a signal providing one of the identified hard-linked services and then determines the quality of the signal using the signal quality detection unit 306. If the received signal is of an acceptable level the processor 309 sends the received signal to the audio output module 311. If the received signal is not of an acceptable level the processor 309 determines if the service following information 211 identifies another hard-linked DAB service for the user-selected service and if so, the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to the next signal providing a hard-linked DAB service and tests the quality of the signal. This is repeated until a DAB signal with an acceptable level is located or there are no more hard- linked DAB services identified in the service following information 211. If the service following information 211 specifies more than one hard-linked DAB service then their quality may be tested in a predetermined order (e.g. a priority order) or in a random order.

[0053] If the processor 309 is unable to locate an acceptable signal providing a hard-linked DAB service then the processor 309 determines if the stored service following information 211 identifies any hard-linked services of other bearers. If so, the processor 309 systematically tunes a receiver for that bearer (e.g. FM radio receiver 312) to each broadcast signal providing an identified hard-linked service one at a time until a signal of an acceptable level is located or all of the identified hard-linked services on other bearers have been assessed. [0054] If the processor 309 is unable to locate any acceptable signal providing a hard-linked service then the status of the DAB receiver 210 may be changed to "service following phase three". During phase three, the processor 309 attempts to locate an acceptable broadcast signal providing a soft-linked service for the user selected service based on the locally stored service following information 211. In particular, the processor 309 determines if the stored service following information 211 identifies any soft-linked services for the user-selected service. As described above, a soft-linked service is one that provides similar, but not identical content. A soft-linked service may be a DAB service or a service on another bearer.

[0055] If the service following information 211 identifies at least one soft-linked DAB service for the user-selected service then the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to a DAB signal providing one of the identified soft-linked DAB services and then determines the quality of the signal using the signal quality detection unit 306. If the received signal is of an acceptable level the processor 309 sends the received signal to the audio output module 311 . Since a soft-linked service does not provide identical content, to avoid confusion to the user, the user may be prompted to accept the selected service before outputting the selected service.

[0056] If the received signal is not of an acceptable level the processor 309 determines if the service following information 21 1 identifies another soft-linked DAB service for the user- selected service and if so, the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to a DAB signal providing the next soft-linked DAB service and tests the quality of the signal. This is repeated until an acceptable signal providing a soft-linked DAB service is located or all of the identified soft-linked DAB services have been assessed.

[0057] If the processor 309 is unable to locate a sufficient signal providing a soft-linked DAB service then the processor 309 determines if the service following information 211 identifies any soft-linked services of other bearers. If so, the processor 309 systematically tunes a receiver for that bearer (e.g. FM radio receiver 312) to signals providing each of the identified soft-linked services of other bearers until a signal of an acceptable level is located or all of the identified hard-linked services have been assessed.

[0058] The above phases may continue until service reception is restored or the user manually selects another service. Generally DAB services are prioritized over other bearer services.

[0059] It will be evident to a person of skill in the art that the above description is an example of how the DAB receiver 210 may be configured to perform service following and that in other examples the service following may comprises more or fewer steps and/or different information may be taken into account in identifying hard-linked and soft-linked services. [0060] An example service following procedure 310 which may be executed by the processor 309 is described with reference to FIG. 6.

[0061] The DAB receiver 210 may also comprise a data communications interface 314 for receiving and transmitting information. In particular, the data communications interface 314 can be used to receive and update the service following information 211 from a user. The data communications interface 314 may, for example, be a wireless communication module that supports one or more wireless data communication technologies (e.g. Wi-Fi™,

Bluetooth™); and/or a wired communication module that supports one or more wired data communication technologies (e.g. Ethernet).

[0062] The DAB receiver 210 may also comprise a computer readable medium interface 315 for receiving a computer readable medium, such as a USB memory device. Such a computer readable medium interface 315 can be used to transfer data between the DAB receiver 210 and the computer readable medium inserted therein or connected thereto. In particular, the computer readable medium interface 315 may be used to receive and update the service following information 211. Methods for uploading and updating the service following information 211 to/on the DAB receiver 210 will be described with reference to FIG. 4.

[0063] The DAB receiver 210 may also comprise an output module 316 for providing information to the user. For example, the output module 316 may be a display device for displaying information, such as the currently selected/connected radio broadcast signal. The output module 316 may be internal or external to the DAB receiver 210.

[0064] In some cases, the processor 309 may be configured to only use the service following information 211 to implement service following if valid service following information (e.g. soft- link and/or hard-link information) is not broadcast as part of the user-selected DAB signal. The user may have the ability to enable or disable this feature. For example, this

configuration may be only activated if the user has provided an indication (e.g. via the input module 305) that they would like to use the broadcast information unless it is not available.

[0065] Reference is now made to FIG. 4 which illustrates methods of providing the service following information 211 to the DAB receiver 210.

[0066] In some cases, the service following information 211 is manually provided or input to the DAB receiver 210 by a user 402. For example, a user 402 may use the input module 305 and/or the output module 316 to manually input the service following information 211.

[0067] In other cases, the service following information 211 is transferred to the DAB receiver 210 by placing the service following information on a computer readable medium 404, such as a USB memory device, and then connecting the DAB receiver 210 to the computer readable medium 404 (e.g. inserting the USB memory device into the computer readable medium interface 315 of the DAB receiver 210). The service following information 211 may be updated in the same, or a similar, manner.

[0068] In still other cases, the service following information 21 1 is provided to the DAB receiver 210 via a portable internet-enabled device 406, such as a mobile phone or tablet. For example, the portable internet-enabled device 406 may have an application which is capable of obtaining service following information from a remote server 408 (via, for example a data communications network 410) and then providing it to the DAB receiver 210. In some cases the application running on the portable internet-enabled device 406 may be configured to automatically obtain the latest service following information on a regular basis (i.e. once a day). In other cases the application may be configured to obtain the latest service following information when it receives an indication from the user that the service following information is to be obtained.

[0069] The portable internet-enabled device 406 may have the ability to transfer the service following information obtained from the remote server via a wireless communications connection (e.g. WiFi™, Bluetooth™, Near Field Communication (NFC), TransferJet™, Wireless USB, ZigBee™ or similar) as shown in FIG. 4 (e.g. via data communications interface 314). Where the portable internet-enabled device 406 has the capability to transfer the service following information wirelessly the application may be configured to automatically transfer the service following information 211 when it establishes wireless communication with the DAB receiver 210.

[0070] Alternatively, or in addition to the wireless capability, the portable internet-enabled device 406 may have the ability to transfer the service following information 211 obtained from the remote server 408 via a wired or physical communication connection. For example, the portable internet-enabled device 406 may have the ability to transfer the service following information via a cable (e.g. a USB cable or an Ethernet cable) when the portable internet- enabled device 406 is physically connected to the DAB receiver 210.

[0071] In some cases the portable internet-enabled device 406 may transfer the service following information 211 via an indirect connection with the DAB receiver 210. In particular, the portable internet-enabled device 406 may directly transfer, via a wired or wireless connection, the service following information 211 to an intermediary device (not shown) and then the intermediary device may transfer the service following information 211 to the DAB receiver 210. For example, if the DAB receiver 210 is situated in a vehicle (e.g. car) then the portable internet-enabled device 406 may transfer the service following information 211 via a wired or wireless communication connection to the vehicle and then the vehicle may transfer the service following information via wired or wireless communication to the DAB receiver 210.

[0072] In yet other cases, the service following information 211 may be generated by the DAB receiver 210 and/or an external device (e.g. remote server 408) based on user patterns etc. For example, in some cases the DAB receiver 210 may be configured to identify and/or record manual changes the user makes to the selected station or service and automatically update the soft-links based on the manual changes identified. For example, the DAB receiver 210 may identify that when Heart Reading dropped out the user selected Classic FM and then automatically create a soft link between Heart Reading and Classic FM.

[0072] In another example, the DAB receiver 210 may be configured to identify and store user listening information (including for example, date and time of selection and duration of time that station/service was listened to) and when the DAB receiver 210 has established a direct or indirect wired or wireless connection with the portable internet-enabled device 406 the DAB receiver 210 may transfer the stored user listening information to the portable internet-enabled device 406 for transfer to an external device (e.g. remote server 408) for analysis. The external device (e.g. remote server 408) may be configured to analyze the user listening information to identify user preferences etc. which can be used to develop a list of soft-linked services and this list can be subsequently downloaded to the DAB receiver 210 via the portable internet-enabled device 406.

[0073] Once the portable internet-enabled device 406 has established a wired or wireless communications connection with the DAB receiver 210 the portable internet-enabled device 406 may also transmit, in addition to the service following information 211 or updates thereto, other useful information. For example, the portable internet-enabled device 406 may provide the DAB receiver 210 with one or more of the following: location information (e.g. GPS (Global Position System) information) that allows the DAB receiver 210 to identify relevant service following information 211 and/or services based on the user's (i.e. portable internet- enabled device's) current position; current speed at which the user (i.e. portable internet- enabled device 406) is currently travelling/moving that allows the DAB receiver 210 to adjust certain operating parameters (e.g. Doppler shift characteristics) to improve the performance of the DAB receiver 210 and/or to send a warning message to the user (e.g. that the vehicle they are in is moving too fast); and/or user preferences to set a number of presets to the user preferences.

[0074] In other examples, when the DAB receiver 210 is installed in a moving vehicle such as a car, the portable internet-enabled device 406 may alternatively or in addition provide the DAB receiver 210 with information that can be provided to the vehicle control system (e.g. processor) to set certain vehicle configurations such as climate, seating position/ergonomics and/or driving style.

[0075] Reference is now made to FIG. 5 which illustrates exemplary service following information 211 which may be stored locally by the DAB receiver 210. The example service following information of FIG. 5 comprises a number of rows 502_!-502₄ and columns 504 504 ₅. Each row relates to a specific set of signals that are linked - i.e. either hard-linked or soft-linked. Such as set is referred to herein as a linkage set. While the service following information 211 of FIG. 5 comprises four rows it will be evident to a person of skill in the art that the service following information may have more or fewer rows depending on the number of linkage set that are supported.

[0076] The columns 504_Γ504 ₅ provide data that allows service following to be implemented for that linkset. Specifically, each column 504 -504 ₅ provides information uniquely identifying a particular signal that is either hard-linked or soft-linked to the other signals in the same row. The first nine columns 504_Γ504₉ provide information that uniquely identifies DAB signals that are hard-linked to each other. As described above, a hard-linked service is a service which has a different service ID (Sid) but provides identical audio and/or data content to the other DAB services identified in columns 504 -504₉. Accordingly, for each row of the service following information 211 , each DAB service identified in columns 504_!-504₉ provides identical content to the other DAB services identified in columns 504 -504₉.

[0077] The remaining six columns 504 ₀-504 ₅ provide information that uniquely identifies services that are soft-linked to the hard-linked DAB services identified in columns 504 -504₉. As described above a soft-linked service is a DAB, or other service, that provides similar content to the DAB services defined in columns 504_Γ504₉.

[0078] Each DAB service is identified by its Sid, Eld and frequency. Whereas services of other bearers (e.g. FM) are identified using other information. For example, the soft-linked FM signals in the linkage sets in rows three and four 502₃ and 502₄ are identified by a PI and a frequency.

[0079] It can be seen than in the example service following information 211 of FIG. 5 the linkage set in the first row comprises three hard-linked DAB services and no-soft linked services; the linkage set in the second row has three hard-linked DAB services and no-soft linked services; the linkage set in the third row has two hard-linked DAB services, one soft- linked DAB service and one soft-linked FM service; and the linkage set in the fourth row has one hard-linked DAB service and one soft-linked FM service. [0080] As described above, if the DAB receiver loses any of the DAB services referred to in any of columns 504 -504 ₅ it can automatically switch to one of the hard-linked or soft-linked services in the same linkage set (e.g. same row) as the lost DAB service identified in the service following information (if available) in accordance with a service following procedure. An example service following procedure 310 is described with reference to FIG. 6.

[0081] It will be evident to a person of skill in the art that the service following information 211 of FIG. 5 is an example only and other service following information may comprise more, less or different information to identify signals, services and soft-linked and hard-linked services. For example, in other examples the service following information may also have geographic information about each of the listed signals/services. In these examples, the DAB receiver 210 may only be provided with a subset of the service following information based on the geographic region they are currently located. This would significantly reduce the amount of service information data stored by the DAB receiver 210.

[0082] Furthermore, while in the example service following information 211 of FIG. 5 the DAB services are defined by an Sid, Eld and frequency, in other examples DAB services may be defined more or fewer elements. For example, in some cases DAB signals may be further identified and defined by an Extended Country Code (ECC). As is known to a person of skill in the art an ECC can be used to differentiate or link the same Sid from different countries.

[0083] The service following information 211 may be generated by, for example, a third party based on knowledge of the DAB services and signals and stored on a server 408 where it can be transferred to the DAB receiver 210 using any of the service following transfer methods described with reference to FIG. 4. Any updates to the service following information 211 may be automatically provided to the end-user who can then provide them to the DAB receiver 210 using any of the service following information transfer method described with reference to FIG. 4.

[0084] In some cases the user may have the ability to edit or otherwise modify the service following information 211 that is stored by the DAB receiver 210. This allows the user to setup the service following information in accordance with their preferences in a manner that would not otherwise be offered by the standard DAB service following. Specifically it allows the user to customize their listening preferences. For example, the user may have the ability to configure the service following information 211 so that if a certain service is not available the DAB receiver 210 will automatically connect to another service even if these two services would not otherwise be linked or connected (e.g. the services may not be hard-linked or soft- linked). For example, the user may be able to specify that if a particular news service is not available to automatically connect to a particular music service. The news service and music service would not typically be linked or connected since a news service is unlikely to provide the exact or similar content to a music service.

[0085] In some cases the user may be able to manually edit the service following information via the DAB receiver itself using, for example, a display and input module of the DAB receiver 210. In other cases, the user may be able to edit the service following information using another device. For example, if the service following information is provided to the DAB receiver by a portable internet-enabled device 406 the user may be able to edit the service following information 211 using the portable internet-enabled device 406. The edited service following information 211 may then be provided to the DAB receiver 210. Any changes made to the service following information 211 via the portable internet-enabled device 406 may be uploaded to a remote server 408. This allows the user preferences to be recovered if the service following information is lost or corrupted. It also allows the user preferences to be applied to other DAB receivers.

[0086] Reference is now made to FIG. 6 which illustrates an exemplary service following procedure 310 which may be executed by the DAB receiver 210 of FIG. 3. At block 602, the DAB receiver 210 receives a DAB service selection from the user. The DAB service may be identified by an Sid, Eld and a frequency. Once the DAB service selection has been received from the user, the method 600 proceeds to block 604.

[0087] At block 604, the DAB radio receiver 302 is tuned to the DAB signal corresponding to the selected service. For example, the tuner 304 may be provided with the frequency of the selected DAB service which causes the DAB radio receiver 302 to be tuned to the specified frequency. The DAB radio receiver 302 may then be provided with the specified Sid so that it can select and decode the appropriate service from the DAB ensemble signal. Once the DAB radio receiver 302 is tuned to the identified DAB signal the method 600 proceeds to block 606.

[0088] At block 606, the signal quality detection unit 306 monitors the quality of the received DAB signal. The signal quality detection unit 306 may use any suitable measurement, such as signal strength, carrier to noise ratio (CNR), signal to noise ratio (SNR), symbol error rate (SER), bit-error rate (BER) etc., for assessing the quality of the received DAB signal. The method 600 then proceeds to block 608.

[0089] At block 608, the signal quality detection unit 306 determines whether the received signal has fallen below an acceptable level. In some cases the signal quality detection unit 306 may determine that the received DAB signal has fallen below an acceptable level if the quality of the signal has fallen below a predetermined threshold. The predetermined threshold may be fixed or may be adjustable by the user. If the signal quality detection unit 306 determines that the quality of the received DAB signal has not fallen below an acceptable level then the method proceeds back to block 606 where the received DAB signal continues to be monitored. If, however, the signal quality detection unit 306 determines that the quality of the received DAB signal has fallen below an acceptable level then the method proceeds to block 610.

[0090] At block 610, the processor 309 attempts to locate an alternate DAB signal providing a service with the same Sid as the user selected service. The processor 309 may attempt to locate an alternate DAB signal providing a service with the same service ID as the selected service by controlling the tuner 304 so as to continually adjust the frequency of the DAB radio receiver 302 until the signal quality detection unit 306 detects that the received DAB signal is of an acceptable level. Once the received DAB signal is of an acceptable level the processor 309 analyzes the DAB signal to determine the one or more service IDs (Slds) associated with the signal. If one of the Slds of the received DAB signal matches the Sid of the user selected service then the method 600 proceeds to block 612 where the signal is sent to the audio output module 311.

[0091] If, however, the Sid of the received signal does not match the Sid of the user selected service then the processor 309 may be configured to continue through the frequencies until either a Sid match is found or all of the frequencies have been analyzed. In accordance with the DAB service following standard, the processor 309 may be configured to prioritize frequencies that transmit the same ensemble as the user selected service. If the processor 309 is unable to locate an alternate DAB signal providing a service with the same Sid then the method 600 proceeds to block 614.

[0092] At block 614, the processor 309 attempts to locate a DAB signal that provides a hard- linked DAB service for the service selected by the user based on the locally stored service following information 211. In particular, the processor 309 determines if the service following information 211 specifies any hard-linked services for the user-selected service. As described above, a hard-linked service is one that provides the same service as the user selected service using a different Sid.

[0093] If the service following information 211 specifies at least one hard-linked DAB service for the user-selected service then the processor 309 tunes the DAB radio receiver to a signal providing one of the identified hard-linked services and then determines the quality of the signal using the signal quality detection unit 306. If the received signal is of an acceptable level the method 600 proceeds to block 616 where the processor 309 sends the received signal to the audio output module 31 1. [0094] If the received signal is not of an acceptable level the processor 309 determines if the service following information 211 identifies another hard-linked DAB service for the user- selected service and if so, the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to the next signal providing a hard-linked DAB service and tests the quality of the signal. This is repeated until a DAB signal with an acceptable level is located or there are no more hard- linked DAB services identified in the service following information 211. If the service following information 211 specifies more than one hard-linked DAB signal then their quality may be tested in a predetermined order (e.g. a priority order) or in a random order. If the processor 309 is unable to locate an acceptable DAB signal providing a hard-linked DAB service then the method 600 proceeds to block 618.

[0095] At block 618, the processor 309 determines if the service following information 21 1 identifies any hard-linked services of other bearers. If so, the processor 309 systematically tunes a receiver for that bearer (e.g. FM radio receiver 312) to each signal providing an identified hard-linked service one at a time until a signal of an acceptable level is achieved or all of the identified hard-linked services have been assessed. If the processor 309 is able to locate a hard-linked service of another bearer, then the method proceeds to block 620 where the processor 309 sends the received signal to the audio output module 311. If, however, the processor 309 is unable to locate any acceptable broadcast signal providing a hard-linked service then the method 600 proceeds to block 622.

[0096] At block 622, the processor 309 attempts to locate a DAB signal providing a soft- linked DAB service for the user selected service based on the locally stored service following information 211. In particular, the processor 309 determines if the service following information 211 specifies any soft-linked DAB services for the user-selected service. As described above, a soft-linked service is one that provides similar, but not identical content.

[0097] If the service following information 211 identifies at least one soft-linked DAB service for the user-selected service then the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to a signal providing one of the identified DAB services and then determines the quality of the signal using the signal quality detection unit 306. If the received signal is of an acceptable level the method 600 proceeds to block 624 where the processor 309 sends the received signal to the audio output module 31 1.

[0098] If the received signal is not of an acceptable level the processor 309 determines if the service following information 21 1 identifies another soft-linked DAB service for the user- selected service and if so, the processor 309 tunes (via tuner 304) the DAB radio receiver 302 to a signal providing the next soft-linked DAB service and tests the quality of the signal. This is repeated until an acceptable DAB signal providing a soft-linked DAB service is located or if all the soft-linked DAB services identified in the service following information 211 have been assessed. If the processor 309 is unable to locate an acceptable DAB signal providing a soft- linked DAB service then the method proceeds to block 626.

[0099] At block 626 the processor 309 determines if the service following information 211 identifies any soft-linked services of other bearers. If so, the processor 309 systematically tunes a receiver for that bearer (e.g. FM radio receiver 312) to each signal providing an identified soft-linked services one at a time until a signal of an acceptable level is located or all of the identified soft-linked services have been assessed. If the processor 309 is able to locate an acceptable broadcast signal providing a soft-linked service then the method proceeds to block 628 where the processor 309 sends the received signal to the audio output module 31 1. Since a soft-linked service does not provide identical content, to avoid confusion to the user, the user may be prompted to accepted the selected service before outputting the selected service. If, however, the processor 309 is unable to locate an acceptable broadcast signal providing a soft-linked service then the method 600 ends 630.

[0100] As described above, in some cases the processor 309 may be configured to only use the service following information 211 to implement service following if valid service following information (e.g. soft-link and/or hard-link information) is not broadcast as part of the user- selected DAB signal. In these cases method 600 may be modified so that if in block 610 the processor 309 is unable to locate an alternate DAB signal providing a service with the same Sid then the processor 309 determines if valid service following information (e.g. soft-link and/or hard-link information) is broadcast as part of the user-selected signal. In these cases, only if the processor 309 determines that valid service following information is not broadcast as part of the user-selected signal does the method proceed to block 614 where the processor 309 uses the stored service following information 211.

[0100] The term 'processor' and 'computer' are used herein to refer to any device, or portion thereof, with processing capability such that it can execute instructions. Those skilled in the art will realize that such processing capabilities are incorporated into many different devices and therefore the term 'computer' includes set top boxes, media players, digital radios, PCs, servers, mobile telephones, personal digital assistants and many other devices.

[0101] Those skilled in the art will realize that storage devices utilized to store program instructions can be distributed across a network. For example, a remote computer may store an example of the process described as software. A local or terminal computer may access the remote computer and download a part or all of the software to run the program.

Alternatively, the local computer may download pieces of the software as needed, or execute some software instructions at the local terminal and some at the remote computer (or computer network). Those skilled in the art will also realize that by utilizing conventional techniques known to those skilled in the art that all, or a portion of the software instructions may be carried out by a dedicated circuit, such as a DSP, programmable logic array, or the like.

[0102] Memories storing machine executable data for use in implementing disclosed aspects can be non-transitory media. Non-transitory media can be volatile or non-volatile. Examples of volatile non-transitory media include semiconductor-based memory, such as SRAM or DRAM. Examples of technologies that can be used to implement non-volatile memory include optical and magnetic memory technologies, flash memory, phase change memory, resistive RAM.

[0103] A particular reference to "logic" refers to structure that performs a function or functions. An example of logic includes circuitry that is arranged to perform those function(s). For example, such circuitry may include transistors and/or other hardware elements available in a manufacturing process. Such transistors and/or other elements may be used to form circuitry or structures that implement and/or contain memory, such as registers, flip flops, or latches, logical operators, such as Boolean operations, mathematical operators, such as adders, multipliers, or shifters, and interconnect, by way of example. Such elements may be provided as custom circuits or standard cell libraries, macros, or at other levels of abstraction. Such elements may be interconnected in a specific arrangement. Logic may include circuitry that is fixed function and circuitry can be programmed to perform a function or functions; such programming may be provided from a firmware or software update or control mechanism. Logic identified to perform one function may also include logic that implements a constituent function or sub-process. In an example, hardware logic has circuitry that implements a fixed function operation, or operations, state machine or process.

[0104] Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person.

[0105] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0106] Any reference to 'an' item refers to one or more of those items. The term 'comprising' is used herein to mean including the method blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and an apparatus may contain additional blocks or elements and a method may contain additional operations or elements.

Furthermore, the blocks, elements and operations are themselves not impliedly closed. [0107] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. The arrows between boxes in the figures show one example sequence of method steps but are not intended to exclude other sequences or the performance of multiple steps in parallel. Additionally, individual blocks may be deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought. Where elements of the figures are shown connected by arrows, it will be appreciated that these arrows show just one example flow of communications (including data and control messages) between elements. The flow between elements may be in either direction or in both directions.

[0108] It will be understood that the above description of a preferred embodiment is given by way of example only and that various modifications may be made by those skilled in the art. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention.

Claims

1. A digital broadcast receiver comprising:

an interface configured to receive service following information from a user;

a storage module configured to store the received service following information; a digital broadcast receiver module configured to receive a digital broadcast signal; a signal quality detection unit configured to monitor the quality of the received digital broadcast signal; and

a processor configured to, in response to the signal quality detection unit detecting the quality of the received digital broadcast signal is below an acceptable level, select an alternate broadcast signal to receive based on the stored service following information.

2. The digital broadcast receiver of claim 1 , wherein the interface is configured to

receive the service following information from a portable internet-enabled device.

3. The digital broadcast receiver of claim 2, wherein the interface is a wireless

communication module that is configured to wirelessly receive the service following information from the portable internet-enabled device.

4. The digital broadcast receiver of claim 2, wherein the interface is a wired

communication module that is configured to receive the service following information from the portable internet-enabled device via a wired connection between the wired communication module and the portable internet-enabled device.

5. The digital broadcast receiver of any of claims 2 to 4, wherein the interface is

configured to automatically receive the service following information from the portable internet-enabled device in response to the interface establishing a data

communications connection with the portable internet-enabled device.

6. The digital broadcast receiver of any of claims 2 to 5 wherein the portable internet- enabled device has received the service following information from a remote server over a data communications network.

7. The digital broadcast receiver of claim 1 , wherein the interface is a computer

readable medium interface configured to receive the service following information from a computer readable medium connected thereto.

8. The digital broadcast receiver of any preceding claim, wherein the service following information comprises one or more user specified preferences.

9. The digital broadcast receiver of claim 8, wherein the one or more user specified preferences comprises a user-created link between a first broadcast service and a second broadcast service.

10. The digital broadcast receiver of any preceding claim, wherein the service following information comprises one or more links between broadcast signals.

11. The digital broadcast receiver of any preceding claim, wherein the received service following information comprises service following information related to a geographical location of the digital broadcast receiver.

12. The digital broadcast receiver of any preceding claim, wherein the interface is further configured to receive an update to the stored service following information from the user.

13. The digital broadcast receiver of any preceding claim, wherein the processor is further configured to update the stored service following information based on an identified user pattern.

14. The digital broadcast receiver of any preceding claim, wherein the processor is further configured to: determine whether service following information is broadcast as part of the digital broadcast signal, and only select an alternate broadcast signal to receive based on the stored service following information in response to determining that service following information is not broadcast as part of the digital broadcast signal.

15. A method of implementing service following using a digital broadcast receiver, the method comprising:

receiving at the digital broadcast receiver service following information from a user; storing the received service following information at the digital broadcast receiver; receiving a digital broadcast signal at the digital broadcast receiver;

monitoring the quality of the received digital broadcast signal; and

in response to detecting the quality of the received digital broadcast signal is below an acceptable level, selecting an alternate broadcast signal to receive based on the stored service following information.

16. The method of claim 15, wherein the service following information is received from a portable internet-enabled device.

17. The method of claim 16, wherein the service following information is wirelessly

received from the portable internet-enabled device.

18. The method of claim 16, wherein the service following information is received via a wired connection between the digital broadcast receiver and the portable internet- enabled device.

19. The method of any of claims 16 to 18, wherein the digital broadcast receiver

automatically receives the service following information from the portable internet- enabled device when the digital broadcast receiver establishes a data

communications connection with the portable internet-enabled device.

20. The method of any of claims 16 to 19 wherein the portable internet-enabled device has received the service following information from a remote server over a data communications network.

21. The method of claim 15, wherein the service following information is received from a computer readable medium connected to the digital broadcast receiver.

22. The method of any of claims 15 to 21 , wherein the service following information comprises one or more user specified preferences.

23. The method of claim 22, wherein the one or more user specified preferences

comprises a user-created link between a first broadcast service and a second broadcast service.

24. The method of any of claims 15 to 23, wherein the service following information comprises one or more links between broadcast signals.

25. The method of any of claims 15 to 24, wherein the received service following

information comprises service following information related to a geographical location of the digital broadcast receiver.

26. The method of any of claims 15 to 25, further comprising receiving an update to the stored service following information from the user.

27. The method of any of claims 15 to 26, further comprising updating the stored service following information based on an identified user pattern.

28. The method of any of claims 15 to 27, further comprising determine whether service following information is broadcast as part of the digital broadcast signal, and only selecting an alternate broadcast signal to receive based on the stored service following information in response to determining service following information is not broadcast as part of the digital broadcast signal.