Standard radio systems may begin with only a few handheld radios and this type of system can be very effective when only an on-site, e.g. 1km radius, service area is required and where there are few obstructions to radio signals within the site. These handheld systems typically operate on a single-frequency channel with the option of adding channels if multi channel or private communications is required.
However, adding radio channels may increase the licence fee (if required) but we can advise whether the existing handhelds may be updated to enable user groups to operate on the original channel without each group overhearing the other group(s) and also assist with the application to Ofcom for new radio licences or changes to existing licences, e.g. additional channel(s). The administration for this service is offered free of charge to clients.
If obstructions to handheld signals cause unacceptable dead spots within the service area it is recommended that the radio system is updated to include a repeater station. A basic repeater system operates with 2 frequency channels where one frequency is used by the handhelds to transmit to the repeater and the second frequency is used by the repeater to automatically retransmit to the remaining handhelds. The repeater’s antenna is typically mounted at a high point near the centre of the service area where the type of antenna will depend on where the users are located within the service area.
A poor or incorrect antenna or a change in the concentration of users may result in poor system coverage. Wall to Wall Radio Communications offers comprehensive site surveys to establish the best type of antenna to be used. Typically, a high-gain antenna may be recommended where good coverage is also required at the periphery of the service area. Alternatively, a down-fire antenna may be recommended where the main users are within a tall building below the antenna site.
When a repeater system has the optimum antenna but there are still coverage problems then a second antenna, connected in parallel with the original, may be required. The site survey would identify the cause of the poor coverage and recommend the type and location of a second antenna.
Systems that have good coverage of the service area but are experiencing traffic congestion may require an additional radio channel. Wall to Wall Radio Communications can advise on this option and assist with the application to Ofcom for an additional channel, if required for this specific purpose.
Repeater systems that require their service areas to be widened, perhaps to enable vehicular mobile radios to be used many km from the existing area, may require a change to the original antenna setup and are likely to require an increase in the licensed transmitter power and the site survey would identify the necessary changes to the system to enable wide-area coverage.
Additionally, repeater systems, both on-site and wide-area, can be linked so that a user transmitting at one site can be received at other sites. Wall to Wall Radio Communications bespoke systems advisors can advise on the various methods of achieving this.
How to reduce the interference to your radio system ?
There are several changes you could make to your radio system that may reduce the signal interference it receives. Reasons for interference are various but the following tips usually solve the most common ones:
>> probably the most simple but may not be practicable in dense urban areas where there may be a severe shortage of spare channels
>> changing from a Shared to an Exclusive Use channel should help significantly
>> this may be as simple as activating the CTCSS or changing the current CTCSS code. This will result in your only hearing the stations using the same code
>> this will reduce the interference from distant stations. NB: check that the revised gain will be sufficiently high to ensure sufficient reception from your mobile / handheld radios
>> this will dramatically reduce the interference from distant stations, e.g. to 100th. NB: check that the revised coverage pattern will remain sufficiently wide to ensure adequate reception from your mobile / handheld radios
>> this method can also be used to increase weak radio coverage directly below an antenna, e.g. within tall office blocks. It may also result in a significant reduction in your licence fee
>> adding a down-tilt of, say, 10 degrees may reduce the interference from distant stations whilst perhaps increasing the signals from your handhelds and mobiles. NB: more interference may occur if the antenna is mounted on a high mast and the amended tilt angle is then directed towards the horizon
>> this will reduce the interference from distant stations. NB: check that the revised height will be sufficiently high to ensure sufficient coverage of your radio system
>> inter-modulation products within a receiver can result in the reception of stations that aren’t transmitting on the selected frequency. This can be caused by the transmissions of two strong nearby radio systems mixing in the receiver and causing ghost stations. Changing to an alternative channel is probably the easiest solution, assuming that one is available in your area.
If the above tips do not make a significant difference or you encounter difficulties trying them out yourself, our Two Way Radio Systems Team will be happy to discuss your interference problems, identify the issues and recommend suitable solutions.
Create Your Two Way Radio System Planning Wish List
Wall to Wall Radio Communications' system engineers have created a questionnaire to help you decide the basic requirements of your new / upgraded radio system. The answers and subsequent discussions will help us to design and supply the best radio system to meet your needs.
DOWNLOAD QUESTIONNAIRE
You can also print this list, answer the questions and send it back to us via fax.
How to reduce your two-way radio licence fee ?
In the following article we provide a list of things that you could consider and take the opportunity to change in your existing two way radio licence in order to save on unnecessary high OFCOM business radio licencing fees. Every piece of advice given below is legal and with this educational material we try to demonstrate our commitment to your business needs and sensibility to your budgets.
Wall to Wall Radio Communications' team wishes you a wonderful Christmas. We hope to stay your partner of choice through the whole 2012 and beyond.
OFCOM uses three basic licence fee structures for private mobile radio (PMR) equipment operation in the UK:
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TECHNICALLY ASSIGNED LICENCES
Ofcom licence fees for these systems include a combination of the following:
The following changes may therefore have a significant effect on your licence fee either now or as part of a system upgrade:
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AREA DEFINED LICENCES
Ofcom licence fees for these systems include a combination of the following:
The following changes may therefore have a significant effect on your licence fee either now or as part of a system upgrade:
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SIMPLE / LIGHT LICENCES
Simple UK (NB: mobiles only for use anywhere within the UK):
Simple Site (NB: may include a low-power base station at a site):
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LICENCE EXEMPT EQUIPMENT
Those would be radios that conform to the relevant requirements, (e.g. Ofcom’s IR2009 for PMR446 walkie-talkies), which may operate on a licence free basis. No licence fee is charged so no fee reduction is possible here.
Wall to Wall Radio Communications will be pleased to discuss your current radio system arrangements with you and suggest ways, including those shown above, in which you may be able to reduce your licence fee.
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