1、ERC REPORT 1 7 European Radiocommunications Committee (ERC) P L A within the European Conference of Postal and Telecommunications Administrations (CEPT) L. -.-,I ._._. HARMONISATION OF FREQUENCY BANDS TO BE DESIGNATED FOR RADIO LOCAL AREA NETWORKS (FUANs) Lisbon, February 1991 Reports are being issu
2、ed from time to time by the European Radiocommunications Committee (ERC) of CEPT to inform industry, operators, users and other interested parties of the work in hand, provisional conclusions and future activities in specific areas of radio frequency management. Such Reports give more details than i
3、s nody possible in a Recommendation and allow an opportunity for comment to be made on the work carried out so far. In most cases, it would be hoped that a formal CEPT Recommendation could be issued on the subject of the Report in due course, taking into consideration any comments received on the Re
4、port. Reports are formally approved by, and issued in the nm of, the Committee itself. In general the detailed preparation of Reports, and further work on the subject, will be done by Workkg Groups or Project Teams. Thus, any reference in the Reports to the ERC should be taken to include the whole f
5、ramework of the ERC, including its Working Groups, Project Teams, etc. MICHAEL GODDARD Chairman European Radiocommunications Committee (ERC) Copyright 1991 the European Conference of Postal and Telecommunications Administrations (CEPT) - - STD.CEPT ERC REPORT II-ENGL L99L II 232b414 OOLC035 638 ERC
6、REPORT 1 Page 1 HARMONISATION OF FREQUENCY BANDS TO BE DESIGNATED FOR RADIO LOCAL AREA NETWORKS (RLANs) 1. INTRODUCTION There is an increasing need for the introduction of computer terminals and peripheral equipment into the business and industrial environments. Currently, information is exchanged b
7、etween such equipment by cable, resulting in a rigid hardware structure. Radio Local Area Networks were conceived in order to replace physical cables for the connection of data networks within a building, thus providing a more flexible and, possibly, a more economic approach to the installation and
8、use of such networks within a building or factory. There are many potential application for UNS and, after an initial consideration, the ERC has come to the preliminary view that more than one technology and frequency band would be necessary to meet the requirements of the various applications. This
9、 report attempts to categorise the various types of RLANs and examine the frequency management issues involved in selection of hannonised frequency bands. It deals with the frequencies for lUANs themselves and does not address the question of the interconnection of individual networks. 2. BACKGROUND
10、 Some countries outside Europe have designated spectrum for RLANs in their ISM bands at 900 MHz, 2.5 GHz and 5.8 GHz. Also, there has been significant development work in the USA on RLANs in the 18 GHz band. Within CEFT, Recommendation T/R 22-03 E provisionally designates the frequency range 59 GHz
11、- 62 GHz for RLANs. Within Europe the DECT system has been developed in the 1880 MHZ - 1900 MHz band offering speech and data facilities which may meet some of the RLAN requirements mentioned above. Compatibility and technical parameters of RLANs will be studied in CCIR Study Group 9 and, in Europe,
12、 the development of equipment standards will be undertaken by ETSI. In CEFT, the newly formed telecommunications regulatory committee, ECTRA, has set up a Project Team to report on the scope for harmonised regulatory policies in the mobile communications field. RLANs will be one of the systems to be
13、 considered. 3. CATEGORIES OF RLANs Three categories of RLANs can be identified: (a) Systems using currently available technology in the low microwave bands. These systems take advantage of spread spectrum modulation techniques, which enable them to operate satisfactorily in a noisy radio environmen
14、t. In the low microwave bands, good in-building penetration may be achieved but systems are limited to low data rates (up to 1 Mbiik) because of spectrum availability. (b) Systems requiring higher data rates and consequently greater bandwidths but smaller range. Such systems are ideally suited to th
15、e millimetric bands. However. the technology has yet to be developed. (c) !$stems requiring reasonable in-building penetration and medium data rates (at least 10 - 15 MbiVs). STD-CEPT ERC REPORT 1-ENGL 1991 I 232b434 0015036 77y ERC REPORT 1 Page 2 4. 4.1. 4.2. 4.3. 5. CONSIDERATION OF FREQUENCY BAN
16、DS For category (a) systems 900 MHz This band is unavailable for RLANs in CEPT countries because of the high density of use by cellular radio. 2.4 GHz - 2.5 GHz This band is designated for ISM applications in all ITU regions. Accordingly it would seem to offer a good alternative to the 9OOMHz band W
17、ithout requiring a significant change to equipment design. However, some CEPT Administrations have expressed the view that they would be unable to designate any of this band for RLANs without a detailed compatibility study with existing radiocommunications systems. 5.725 GHz - 5.875 GHz This band is
18、 also designated for ISM applications in all ITU regions. However, in order to use the band, a design change would be required, delaying the introduction of FLNs, and there would be less in-building penetration at this frequency. Again, some CEPT Administrations have expressed the view that they wou
19、ld be unable to designate any of this band for RLANs Without a detailed compatibility study with their existing radiocommunications systems. Category (b) systems As mentioned above, CEPT Recommendation TIR 22-03 E designates the frequency band 59 GHz - 62 GHz for radio links and RLANs. However, it i
20、s considered that initial RLANs could be accommodated in a smaller sub-band in order to encourage the development of spectrum efficient equipment and similar to the concept of category (a) equipment, the ISM band 61 GHz - 61.5 GHz is recommended. At a later stage, compatibility studies With the fixe
21、d service may enable frequency sharing in all or part of the 59 GHz - 62 GHz band. Category (c) systems An operational system meeting the requirements of this category has been developed in the United States to work in the frequency band 18.8 GHz - 19.2 GHz. In CEPT countries this band is used in ac
22、cordance with the Radio Regulations and CCIR Recommendations for the fixed service. Compatibility studies between the fixed service and the RL,AN system mentioned above are in progress in some CEPT countries. Preliminary results are not encouraging. Further studies are necessary to confirm these res
23、ults and to investigate the possibility of using adjacent bands within the tuning range of equipment. If these studies finally prove negative, it Will be necessary to identify a suitable alternative band to meet the perceived requirement of category (c) systems. PROPOSED ACTION AND TIMESCALES Steps
24、have been taken within the framework of the ERC to provide Administrations with the technical information on category (a) RI,ANs and to prepare example methodologies for compatibility studies between RLANs and existing systems operating in the frequency band 2400 MJ3z - 2500 MHz and 5725 MHz - 5875
25、MHz. This work will include consideration of national compatibility studies between FL4Ns and the fixed service in the 18 GHz band and provide a joint conclusion on the possibility of frequency sharing. Work on category (a) systems is in hand and it is hoped that decisions can be reached in June 1991. If the studies at 18 GHz prove negative, the work will continue to provide a longer term solution to the requirement for category (c) RLANs.
