1、Rec. ITU-R BS.1350-1 1RECOMMENDATION ITU-R BS.1350-1SYSTEMS REQUIREMENTS FOR MULTIPLEXING (FM) SOUNDBROADCASTING WITH A SUB-CARRIER DATA CHANNELHAVING A RELATIVELY LARGE TRANSMISSIONCAPACITY FOR STATIONARY ANDMOBILE RECEPTION(Question ITU-R 71/10)(1998)Rec. ITU-R BS.1350-1The ITU Radiocommunication
2、Assembly,consideringa) there is an increasing requirement worldwide for a suitable means of multiplexing FM sound broadcasting witha sub-carrier data channel having a relatively large transmission capacity for stationary and mobile reception;b) that FM sound broadcasting will support higher capacity
3、 data transmissions;c) that the capacity of current data systems in common use in FM sound broadcasting is limited;d) that technical developments in large capacity data systems for multiplexing with FM sound broadcasting havedemonstrated the technical feasibility of larger capacity data systems;e) t
4、hat field trials and demonstrations have confirmed the feasibility of large capacity data systems for use in FMsound broadcasting;f) that compatibility has been achieved between the FM stereophonic services including the Radio Data System(RDS) services according to Recommendation ITU-R BS.643 and an
5、y new additional sub-carrier system has beendemonstrated;g) that a much larger data capacity may be needed for some applications;h) that sub-carrier data radio channel systems can provide relatively large transmission capacity compared toRDS and are capable of meeting compliance requirements of Reco
6、mmendation ITU-R BS.412;j) that several relatively large transmission capacity data systems according to Recommendation ITU-R BS.1194have already been put into operation,recommends1 that systems for multiplexing FM sound broadcasting with a sub-carrier data channel having a relatively largetransmiss
7、ion capacity for stationary and mobile reception:1) must comply with current ITU policy on intellectual property rights;2 Rec. ITU-R BS.1350-12) must not interfere with: the main broadcast on the same carrier or on adjacent carriers as stated in Recommendation ITU-R BS.412; RDS and/or other sub-carr
8、ier services on the same or adjacent carriers as stated in RecommendationsITU-R BS.412 and BS.643; aeronautical radio navigation services as stated in ITU-R IS.1009;3) should be evaluated for selection taking into consideration the following characteristics and features relative to theneeds of the p
9、articular application:a) system performance characteristics such as: data reliability in Gaussian noise; data reliability in multipath reception conditions; data reliability with adjacent channel signals; shortest end-to-end delay; message error rate for various message lengths in multipath conditio
10、ns; synchronization acquisition time;b) additional features of the system such as: minimum duty cycle for power savings; receiver addressability; conditional access; support for various data types; ability to operate in a network of data services; possibility for additional sub-carrier services; abi
11、lity to operate independently of the radio network; multiple station access; capability for rebroadcasting;c) system compliance with Recommendation ITU-R BS.450;d) the ability of the system to minimize possible degradation to the audio main channel and/or RDS in multipathreception conditions;e) resu
12、lts of field tests of the system;4) should be selected and specified with at least the following general features being identified: sub-carrier frequency; bandwidth; channel data rate; information data rate; modulation method; packet structure and framing (data structure); forward error correction a
13、nd interleaving approach; error detection capability; injection level;5) should be selected depending on the application.NOTE 1 These requirements, considerations and applications are discussed further in Annex 1.Rec. ITU-R BS.1350-1 3ANNEX 1Systems requirements for multiplexing FM sound broadcastin
14、g with asub-carrier data channel having a relatively large transmissioncapacity for stationary and mobile reception1 Introduction1.1 PurposeThe purpose of this document is to assist in the selection of a specific system for providing relatively large datatransmission capacity using sub-carriers mult
15、iplexed with FM sound broadcasts. This document presents a set of systemcharacteristics that should be considered when selecting a system for the above purpose. These characteristics aredivided into four aspects as follows: General Features is an overview of the basic parameters of the data systems
16、(Section 3). Additional Features describes specifics of each data system that will tend to make it more or less suitable forspecial features of each system (Section 4). Compatibility characteristics which relate to the quantitative impact of the data system on existing services, bothon the broadcast
17、 channel using the same carrier as well as on adjacent channels (Section 5). System performance characteristics which relate, in various terms, to the performance of the data system itself(Section 6).It is recognized that compatibility characteristics of a system are important regardless of the appl
18、ication. The systemperformance characteristics are dependent on the specific requirements of the intended application. This documentidentifies the important system performance characteristics for a number of different applications.1.2 Special requirementsAs for all systems recommended by the ITU, th
19、e system chosen should comply with the current ITU policy onintellectual property rights (see Annex 1 to Resolution ITU-R 1). In addition, proposed systems should be field testedprior to selection.2 System applicationsSystem applications are based on receiver characteristics, data types and transmis
20、sion characteristics. These arediscussed in Sections 2.1, 2.2 and 2.3 respectively. A particular system application involves the transmission of one ormore data types from transmitters having various characteristics, to receivers with one or more characteristics. Becauseof the particular data types,
21、 transmitter characteristics and expected receiver characteristics which distinguish any givenapplication, certain system performance characteristics will be more important than others.2.1 Receiver characteristicsReceiver applications are distinguished in terms of the following characteristics. Some
22、 receivers may be good enough tomeet low data rates or reliability requirements, but will not be adequate where high data rates and reliability are required.2.1.1 Physical characteristics of the receiver application availability of prime power to the receiver (battery size and capacity); receiver an
23、tenna performance; receiver mobility and speed of motion; receiver noise figure; ambient electrical noise.4 Rec. ITU-R BS.1350-12.1.2 Data requirements of the receiver application required data integrity; receiver addressability options; data traffic types; networking functions.Several receiver appl
24、ications have been identified as shown in Table 1.TABLE 1Receiver applications2.2 Data typesThere are two data types. Firstly, packetized data which involves communication of information that is naturallyseparated into data segments or messages for some reason. Usually this segmentation is associate
25、d with a header of sometype which may be used for addressing the data to a specific user or otherwise designating something unique about thatsegment of information. Packetized data may be further categorized based on the length of the message. Some may be asshort as a few tens of bits while others m
26、ay be as long as hundreds or thousands of bytes.Secondly, continuous data, which involves the communication of data at a fixed rate in a way that presumes that, if thereis any segmentation of the data, it is accomplished in a higher layer in the protocol stack and frequently consists of asequence of
27、 packets.2.3 Transmission system characteristics signal strength and intended service area; ability of transmitters to address specific receivers; transmitter networking functions.3 General features and parametersThe following general characteristics should be considered when selecting a system: sub
28、-carrier frequency; bandwidth; channel data rate; information data rate; modulation method; packet structure and framing (data structure); forward error correction and interleaving approach; error detection capability; injection level.Application Power availability Receiver antenna performance Mobil
29、ityVehicular High Fair to good 0-150 km/hPortable Low Fair 0-5 km/hPersonal Extremely low Poor 0-300 km/hFixed Very high Good to excellent 0 km/hRec. ITU-R BS.1350-1 54 Additional featuresThe following additional features should be considered when selecting a system: minimum duty cycle for power sav
30、ings; receiver addressability; conditional access; support for various data types; ability to operate in a network of data services; possibility for additional sub-carrier services; ability to operate independently of radio network; multiple station access; rebroadcasting capability.5 Compatibility
31、characteristicsThe following compatibility characteristics should be considered when selecting a system: interference to main broadcast service (on the same carrier); interference to RDS and/or other sub-carrier services (on the same carrier); protection ratio for broadcast services (on adjacent cha
32、nnels); protection ratio for RDS and/or other services; Recommendation ITU-R BS.450; protection ratio for aeronautical radio, Recommendation ITU-R IS.1009; degradation to audio main channel in multipath reception conditions.6 System performance characteristicsThe following system performance charact
33、eristics should be considered when selecting a system: data reliability in the presence of Gaussian noise; data reliability in multipath reception conditions; data reliability in the presence of impulse noise; data reliability with adjacent channel signals; shortest end-to-end delay; message error r
34、ate for various message lengths in multipath conditions; synchronization acquisition time.Data reliability deserves some discussion. These characteristics are determined by the methods of modulation and codingas well as other features of the system. Data reliability performance is typically characte
35、rized in terms of Bit Error Rate(BER), packet loss rate or Probability of Correct Message Received (PCMR) as a function of the conditions in thechannel.For noise, these conditions are normally described in terms of Signal to Noise Ratio (S/N). For multipath and noise, theconditions are described in
36、terms of the multipath delay spread profile and fade rates as well as average S/N. For impulsenoise, the channel is described in terms of peak pulse powers, pulse width and pulse repetition rate. Data reliability ingeneral determines the coverage area and will be affected by the injection level.6 Re
37、c. ITU-R BS.1350-17 Example applicationsA number of items have to be considered as the minimum features required for defining a generic specification of an FMdata broadcasting service. I1 Service channels: A service channel offers a powerful way of managing access to a given service by an end-userte
38、rminal (automatic tuning, service roaming, .). I2 File transfer services: It is desirable that transparent file transfers are managed by the system in order to providea large range of applications using, for instance, standard software on Personal Computers. I3 Real-time services: Some services may
39、need real time or assured maximum delay (Differential GlobalPositioning System (DGPS). I4 Conditional access: Conditional access is a key feature for commercial services.NOTE Service multiplexing: A service identification and management system offers flexibility for broadcastingseveral services toge
40、ther.Compatibility with future DSB services has to be taken into account.If we consider the generic definition of any broadcasting system (according to the ISO Open Systems Interface,seven layer model), these seven key items can be achieved by having a common understanding about the interfaces onlay
41、er 3 (I1), 4 (I3, I4) and 5 (I2).This is the basis of a further discussion. As a summary, a worldwide standard should fulfil the required interfaces.The following sections provide some examples of specific applications in operation or under test, along with a list of thecharacteristics from precedin
42、g sections which are most important for each of these applications.7.1 Intelligent Transportation System (ITS)ITS requires several data types for transmitting transportation related information. Type 1 is for text, intended forportable receivers with small displays. Typically text ranges from 10-100
43、 bytes in volume. Type 2 is for long textual orgraphical information with simple road maps for traffic congestion and is intended for mobile receivers (vehicular).Typical data volumes range from 100 to 5 000 bytes. Type 3 is for transparent data and coded information intended fornavigation, includin
44、g large memory (CD-ROM) equipment having detailed road maps.Data requirements vary greatly. DGPS is an example of Type 3 data requiring short delivery delay ( 10 seconds), at arate of 10s of bytes per second. A message of 10 to 20 bytes may be required for updating databases, perhaps of buslocation
45、or highway status. Since the database updates are used in the vehicle to help the driver determine the best route,and since delayed information can lead to incorrect route decisions for individuals and larger traffic problems for ahighway network, end-to-end delay is an important metric for this ITS
46、 application. The database update messages willtypically be repeated in a cyclic manner. However, since there is such a large volume of data, failure to receive a givenupdate because of channel errors implies that the user must wait for the subsequent broadcasts. This would result in alarger effecti
47、ve delay, degrading vehicular traffic flow.The following characteristics are most important to ITS applications: data reliability in multipath fading and noise; data reliability in the presence of impulse noise; end-to-end delay; information data rate;Rec. ITU-R BS.1350-1 7 synchronization acquisiti
48、on time; error detection and correction capability; implementation cost and risk; standardization.Also, in order to achieve ITS network simplicity and reduce costs, the ability for a system to serve reliably a target areafrom a single transmitter is highly desirable. In addition, system capacity uti
49、lization should be kept as efficient aspossible. Also, to encourage widespread use of ITS information, receivers for the system should be low cost. Inevaluating candidate systems for this application, the characteristics above should be given high priority. A comparisonof candidate systems should be made, paying particular attention to these characteristics.7.2 PagingPaging applications require the broadcast of relatively short packets to personal receivers. One of the criticalcharacteristics for pagin
