ger must therefore monitor all the subsequent batches until it finds one with its own address appended, or it times 45.10.2 ERMES out after 12 seconds. Battery economy is also possible in other ways, but the process becomes complicated. This new European Radio Messaging Service is due to start in In multi-frequency networks the paging receiver will be informed December 1992. The standards are the result of an ETSI Working on which channel to expect its messages. This is accomplished with Group, and are awaiting approval by individual countries before a combination of the frequency subset indicator transmitted in the being fully approved by ETSI. All operators will use the channels system information partition, and the frequency subset number within the 16 allocated, and the same protocol, SO that one operator's stored in the receiver. (See Figure 45.9.) Each pager will be assigned pager will work on another operator's system. a frequency subset number (FSN) between 0 and 15. This identifies Operators in 16 European countries including the UK, France, a unique subset of five frequency subset indicators (FSI). Each FSI Germany and Italy, signed a Memorandum of Understanding, to defines the unique subset of FSNs to which the message may be provide a system that allows international roaming, and would serve directed. The FSI broadcast on a paging channel indicates that each of their capital cities and 25% of total service population (90 messages will be transmitted for pagers with an FSN in that FSIs million people) by December 1993. The pager will scan 16 v.h.f. subset. For example, when the FSI on a channel equals 27, only paging channels, many of which are already used in these countries messages for receivers with FSNs of 12, 13, 14 or 15 will be carried. for other services. Conversely a receiver with FSN equals 12 should look for its Indirect satellite paging 45/17 Sequence 60 min. 60 cycles 56 57 58 59 Cycle 1 min. 5 subsequences Subsequence 12 sec. 16 Batches \BCDEFGHIJKLMNO Batch Sys info Addresses Messages (