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A Common Base Station (CBS), sometimes referred to as a community repeater, is a base station which is installed by an operator to provide a mobile communications service,
on a commercial basis, to a number of independent users. Operators are assigned an area exclusive radio frequency in the VHF or UHF private mobile radio (PMR) Bands and install the base station on a suitable site in the area over which they wish to provide coverage.
Application for a Wireless Telegraphy Act licence to operate a CBS should be made by the prospective operator on form RA 259,
to the appropriate address as shown at the back of this leaflet. A map showing the proposed coverage area must accompany the application.
Due to the demands on the radio spectrum there may be problems finding channels in those areas of the country with the greatest population densities. The application form asks for the preference of frequency band but it may not be possible to assign either a frequency in that, or any, other band. If a channel cannot be found in the requested area, one in a different frequency band may be offered to you instead. If it is not possible to find a channel, the licence fee will be returned and your application will be rejected. Due to the demand on CBS spectrum give your local RA office a call to discuss possibilities before submitting an application.
If there is a possibility of an assignment they will carry out coverage prediction work taking into account topography, the frequency, antenna height and type and erp. The parameters will be adjusted to attempt to match the coverage area requested to that permitted by current CBS planning criteria and minimising interference, as far as possible, to other co-channel users. Antenna parameters will be specified in terms of erp, radiation pattern, downtilt and direction of maximum radiation and we will state an antenna which we believe matches the parameters. It is possible to gain permission to use an alternative antenna installation if it can be shown that the radiation pattern of the installation is equivalent to the radiation pattern of the stipulated antenna. The term 'antenna installation' is used rather than 'antenna' as the structure that the antenna is mounted on, or other nearby structures, may have a significant effect on the radiation pattern.
If the above is successful, before the assignment is formally made the applicant will be provided with details of the proposed operating parameters and asked to give written agreement to the proposal. 14 days will be given in which to reply after which the offer will be withdrawn thus freeing
the channel for other prospective applicants.
Frequencies in UHF 1 are only available within the following areas:
London |
Base |
Base |
|
|---|---|---|---|
| (within 40.5 kms) | |||
| 441 | paired with | 427 | |
| 445 | 425 | ||
| 448 | 431* | ||
| * Frequencies at 12.5 kHz channel separation but based upon 6.25 kHz interleaves. | |||
Within 16 kms radius of the following NGRs
| Aberdeen | NJ 930 050 | |
| Bradford | SE 160 330 | |
| Derby | SK 340 350 | |
| Edinburgh | NT 260 740 | |
| Halifax | SE 080 250 | |
| Leeds | SE 300 340 | |
| Leicester | SK 580 040 | |
| Middlesbrough | NZ 510 180 | |
| Newcastle | NZ 250 640 | |
| Nottingham | SK 570 410 | |
| Preston | SD 530 290 | |
| Sheffield | SK 350 870 |
Outside of London frequencies are only available with Base Tx 441 to 445 and Base Rx 425 to 427.
Coverage is based on a field strength necessary to induce
0.5 µV pd into a 
/4
antenna at 1.5m. For the various bands, this equates to Low Band 6 dB (µV/m);
Mid/High Band 12 dB (µV/m) and UHF 22 dB (µV/m).
Predicted coverage is planned to provide a service radius of 45 kms with an interference range limited to 75 kms (this is defined where the field strength falls to 12 dB below the edge of service levels defined above).
A new licensee is allowed up to two years to reach the minimum loading levels, however, a licence will not be renewed if equipment has not been installed in the first year.
The CBS licence requires licensees to provide an annual statement of the total number of CBS customers to the Radiocommunications Agency no later than six months before the renewal date. Where this information has not been received there is a possibility that we may refuse to renew a licence.
The customer loading needed to retain a licence is a minimum of three separate legal entities, and a minimum traffic density of 10% or 0.1 erlang in the busy hour. The figure for this may be increased depending upon the area of the country and the consequent demand on the spectrum. However, it should be remembered that it is the intention that a CBS should provide a service for a number of users and that single user CBS services will not be permitted. Although it is permissible for some users to have their access time limited, at least three users must have access to the service for the entire 24 hour period.
We will not retrieve an under used channel from a licensee unless there is a demand for spectrum in that area.
If applying for an additional channel to an existing system, the procedure can be speeded up by supplying current loading information at the time of the application. Until we have the loading details and have verified that the assignment of an additional channel is justified, we will not be able to make progress with an application.
The following loading criteria are used when assessing a request for an additional channel and all figures refer to speech traffic. These require that minimum loading levels are met on all existing channels for both busy hour and working day periods. A "working day" is defined as a ten hour period usually between 08:00 to 18:00. The figures apply to each channel.
The above loading levels are based on the coverage model of up to 45 km range. For larger coverage areas loading levels may be increased at the Agency's discretion.
A licensee is required to give agreement to bringing into line with the new assignment criteria all existing assignments that lie within 45 kms and are in the same band as the proposal before the proposal can ordinarily be considered.
Where a licensee has assignments in the same band and at the same site (or at a site giving substantially the same coverage) as the proposal, and where an applicant chooses to not bring these assignments within the current CBS planning criteria, then the Agency may, at its discretion, allow an additional channel if demand in a particular area is low. In these cases, loading requirements for additional channels are adjusted upwards to the following amounts:
| Existing Coverage Radius |
Number of Channels | |||
| 1 | 2 | 3 | 4 | |
| 50 kms | 27% (0.27 erlang) | 56% (0.56 erlang) | 72% (0.72 erlang) | 82% (0.82 erlang) |
| 55 kms | 33% (0.33 erlang) | 68% (0.68 erlang) | 88% (0.88 erlang) | |
| 60 kms | 38% (0.38 erlang) | 82% (0.82 erlang) | ||
| 65 kms | 46% (0.46 erlang) | 95% (0.95 erlang) | ||
| 70 kms | 53% (0.53 erlang) | |||
Some services have evolved with a dominant user which means the CBS operator breaches licence conditions on loading. A procedure has been developed whereby a dominant user will be allowed to obtain a PBR licence for their own system and install equipment, such as that approved to MPT 1301, which may not meet current approval standards.
After a frequency has been assigned a licence will be sent. The Licence document consists of three parts; the first is the licence document which is standard across licence categories; the second part, schedule 1 is applicable to the type of operation required, in this case Common Base Stations, and the third part will be the technical parameters applicable to the particular service. As the Agency's licences are refined into a common format there may be several presentational changes over the next few years.
The licence schedule will set out the frequencies on which the base station must operate and any technical parameters with which the installation must comply. It must be remembered that the radio system must conform with all conditions contained within the licence and failure to do so may render the licensee liable for prosecution.
The licence runs until revoked or cancelled even though failure to conform with the conditions of either the licence or schedule will render the operator in breach of the licence conditions.
It is a licensee's responsibility to ensure that we receive payment for a licence prior to the expiry of a licence. There is no legal requirement for the Agency to issue either a renewal notice or a reminder. Once a licence has expired, no further requests for payment will be sent.
One way of ensuring that a licence does not expire unintentionally is by paying the renewal fee by Direct Debit. Forms are available from your normal RA contact point.
Failure to pay the licence fee when it is due will result in the licence being revoked. Payment should be received by the Agency prior to the renewal date shown on the licence to ensure that the licence is valid for the following year. Once payment has been received a validation document will be issued.
Failure to pay on time is unfair to the majority of licensees who do pay on time and, as with a television licence or car tax disc, it is an offence to operate without a valid licence. If there is a breach of licence conditions we will not make any amendment or enter into any correspondence with that licensee on any of that person's or company's licences.
If a licence is revoked for non payment an operator may apply for a new licence but it may not be possible to issue a new licence for the same or any other radio frequencies. If we have any outstanding requests for spectrum in the area where the base was located those applications will be considered before the re-application. If it is possible to issue a new licence, this assignment will be based on CBS planning criteria current at the time of the application in relation to coverage areas of both the new and existing assignments (if within 45 kms of the new assignment), and loading levels if a multi-channel system. All equipment used on the system will have to meet with current type approval requirements.
Within 5 days of the base station being installed the licensee must notify the Agency's local office. A technical officer will inspect the system to ensure compliance with all sections of the licence and the licence schedule. Commercial use need not await this inspection and may commence as soon as the base station is installed. However, if on inspection the installation is found to vary from the licence conditions the operator will be required to rectify the discrepancies within a set time limit. In case of serious variation, operation may be required to cease immediately.
If a request to move the base station (see below) is to be made, this should be done in sufficient time before renewal. If upon the first renewal date no base station equipment has been installed it is unlikely that we will allow the licence to be renewed.
Fixed trigger stations employed for the remote control of the base station by reverse frequency working must use some form of tone signalling. Talkthrough (mobile to mobile) must also be controlled by tone signalling. Licensees may only use the CTCSS tone groups specified on the schedule. Digital signalling complying with MPT 1317, or DCS in accordance with MPT 1381, or a combination thereof may be used. Tones for all channels are now assigned in blocks of four for CTCSS (see below) and groups of five for DCS. See Information Sheet RA373 for further information on DCS, which includes the assignment sub-groups.
| Tone Signalling Control | |||
| Group A1 | Group A2 | Group A3 | Group A4 |
|---|---|---|---|
| 67.0 | 77.0 | 88.5 | 107.2 |
| 114.8 | 123.0 | 131.8 | 141.3 |
| 151.4 | 162.2 | 173.8 | 186.2 |
| 203.5 | 218.1 | 233.6 | 250.3 |
| Group B1 | Group B2 | Group B3 | Group B4 |
| 71.9 | 82.5 | 94.8 | 103.5 |
| 110.9 | 118.8 | 127.3 | 136.5 |
| 146.2 | 156.7 | 167.9 | 179.9 |
| 192.8 | 210.7 | 225.7 | 241.8 |
In addition to the above tone groups, we will accept applications on a case by case basis for the use of Group C tones on certain channels. For those channels that are used either exclusively for CBS or where there is no possibility of a Private Business Systems assignment within interference range of a CBS, we will allow the use of Group C tones. It should be noted that tests carried out by the Agency have indicated that some equipment failed to correctly decode some tones in Group C and it will be the responsibility of the operator to ensure that all equipment will perform correctly on the newly assigned groups.
These also have been divided into separate sub-groups:
| Tone Signalling Control | ||
| Group C1 | Group C2 | Group C3 |
|---|---|---|
| 69.3 | 74.4 | 79.7 |
| 91.5 | 97.4 | 85.4 |
| 198.0 | 206.5 | |
| 229.1 | 254.1 | |
Where continuous signalling is not used, some form of automatic control must be employed to ensure that the base station transmitter is closed at the end of each message. Systems which rely on the cessation of carrier to close down the base station talkthrough condition are not acceptable.
Where CTCSS is employed, the use of non-predictive CTCSS decoders is encouraged. Such use overcomes the problem of carrier lockout and provides an upgrade path to simple trunking techniques. This type of board may be retro fitted to equipment approved under MPT 1326. However, under ETS 300 086 equipment
must be approved with the decoders already fitted. New equipment approved to MPT 1326 may continue to be installed. It is possible to obtain type approval under I-ETS 300 219 for equipment with boards that are fitted into existing sockets. The testing under this specification is less onerous than full type approval.
Licences are not transferable but it is possible to takeover the commercial service operated by another legal entity. However, if the existing service does not meet our loading requirements for retention of a channel then a takeover will not be permitted.
There is a procedure that must be followed to enable us to agree to a takeover and failure to follow those requirements will result in the takeover being rejected.
Firstly, the service to be taken over must be currently licensed and there must be sufficient time prior to the expiry of a licence to enable us to make full enquiries about the existing system. If we do not have current monitoring information for the area in which the system is located we will need to establish what the loading is on the system after we have received your request.
The request to takeover a service must be made on RA 259 and be accompanied by a letter from a responsible person from the current licensee agreeing to the takeover. The licence fee must accompany the application.
From time to time it may become necessary to move a base station to another site. The new site should offer very similar coverage to the original site. Any requests to move to a site offering a substantially different coverage will be considered as a request for a new licence.
The Agency wishes to encourage the use of trunking as it is a more efficient use of the spectrum and can offer a higher grade of service than a single channel CBS. Licensees wishing to trunk channels should provide the Agency with full details of the access protocols they wish to use. Approval by the RA must be received before trunking of channels may commence. Channels assigned for trunking must be used for that purpose and may not be subsequently disaggregated.
Potential users of MPT 1327 should be aware that the RA does not have a record of the identifier codes in use, so anyone proposing to use this form of signalling should ascertain for themselves which codes are safe to use.
Trigger stations will be permitted without prior authorisation anywhere within the coverage area (as defined by RA) and up to 45 km away from the base station, unless otherwise stated on the licence schedule. The engineering parameters are as follows:
Trigger stations beyond the 45 km limit will only be allowed in exceptional cases and must be approved by your local office, prior to installation. A decision will be given within 10 working days from receipt of an application.
The antenna specified is for transmit only and it may be found useful to employ a different antenna, especially in Low Band, for receive.
Operators shall note that approval for trigger stations beyond 45 kms is unlikely to be granted in or near major conurbations. These restrictions are required to minimise interference to other CBS services.
For new CBS services, all equipment must conform to current type approval standards, ETS 300 086, ETS 300 113 or MPT 1326.
Handportables must conform to ETS 300 296 for speech and ETS 300 341 for signalling. Older equipment already in service may continue to be used at its present location but any additions to a system must meet the current standards. Older equipment may not be moved to other base station sites without specific authorisation which may possibly include the use of directional or downtilted antennas.
The transmission of data is permitted on channels that are not shared either with PBR licensees or other CBS operators within normal re-use distances. Generally, those channels released from the reserve spectrum will pose no problems whereas channels in use previously may not be so easy for us to agree to. Applications will be dealt with on a case by case basis. A document has been produced (RA 355) which identifies those channels for which there should be no problems, these channels are termed 'data compatible' and are marked with an asterisk. A copy has been sent to all CBS Licensees and is available from our library.
For those channels which do not fall into this group, we will still allow the use of data, on a shared channel basis. The policy for this area is under review, please call the CBS section for further information.
For those systems which will employ CTCSS, a different tone must be nominated for use with data than that used for speech. This is to enable our monitoring team to distinguish between data and speech traffic.
Telephone interconnect may be made either with the Public Switched Telephone Network, Private Automatic Branch Exchange or a Private Branch Exchange. The latter is for an internal switchboard where connections are made by the operator.
Calls may be made either from the mobile to the telephone system or in the opposite direction.
Specific approval is no longer required for telephone interconnect but operators should bear in mind that CBSs are intended for passing a large number of short messages. Telephone type calls tend to be longer. For this reason, we will not take into account telephone interconnect calls when assessing channel loading which may have a detrimental affect on either meeting minimum loading requirements or requests for additional channels.
Operators are advised to comply with the following recommendations to avoid excessive channel occupancy or abuse of telephone interconnect:
iii. Ringing tones - 30 seconds
iv. Maximum call duration - 3 minutes
v. Reset if no carrier on receive present - 10 seconds
vi. Re-dialling barrier - 2 minutes
We will consider applications for Frequency inversion, Band inversion, Band scrambling and Rolling Code inversion. Licensees who wish to use voice privacy must gain approval prior to installing equipment and must provide details of the method used, equipment manufacturer and voice privacy algorithm to be adopted. If an application is approved the licence schedule will be amended to include it and the facility may not be used until this confirmation is received.
If a standard PBR user wishes also to subscribe to a CBS service, in order to maintain contact when mobiles are out of range of the customers own licensed service, there are no restrictions providing each use of radio is covered by a valid licence and separate channels are used. e.g. Channel 1 - CBS, Channel 2 - PBR.
Radio alarms may be authorised on
CBS channels. Applications should be accompanied by a letter setting out the technical details of the proposed system. Approval of radio alarms will be subject to the following general conditions:
It may not be widely appreciated that all telecommunications systems which use radio require to be licensed not only under the Wireless Telegraphy Act 1949, dealing with technology and spectrum issues, but also under the Telecommunications Act 1984, (T Act) which regulates the provision of telecommunciations services.
The T Act regulates those operators who run telecommunications systems (networks). Service providers who run only a single site system do not require an individual T Act licence since they are covered by a T Act 'Class Licence'. * Class licences are general legislation which effectively exempt applicable services from the requirement to hold an individual T Act licence and include a 'Self-Provision' class licence (which authorises the majority of Private Business Systems) and a separate class licence covering the provision of services to third parties under certain specific circumstances.
If potential multi-site CBS operators are unclear as to whether their plans to link base stations fall within the scope of the Class Licence, (i.e. whether each base station constitutes a separate applicable system already licensed under the Class Licence or whether the linked base stations are deemed to be a single applicable system requiring an individual T Act licence), they should contact Hugh Robertson at OFTEL (Tel: 020 7634 8832) with a description of the system. If OFTEL advise that the CBS system falls outside the scope of the Class Licence, it will be necessary to apply for an individual T Act licence from DTI (contact: Roger Close on 020 7215 1783 for further details).
* The 'Class Licence for the running of PMR Systems, Radiopaging Systems and Automatic Location Systems for the Provision of Services to Third parties' is available from the OFTEL Research and Intelligence Unit, 50 Ludgate Hill, London EC4M 7JJ (Tel: 020 7634 8761) price £4.
Hopefully we have foreseen any questions you may have but if you would like to discuss your application before submitting it please feel free to discuss it with us.
All applications must be made to your local RA office, details of which can be found on Information Sheet (RA 206).
Girish Patel - 020 7211 0237
girish.patel@ra.gsi.gov.uk
Trevor Allison - 020 7211 0242
trevor.allison@ra.gsi.gov.uk
Fax:020 7211 0117
For further information about radio use contact the RA enquiry point on 020 7211 0211
Radiocommunications Agency
Wyndham House
189 Marsh Wall
London
E14 9SX
| RA 307 (rev 1) June 2003 |
