Ambitalk

Ambitalk is the UK's largest PAMR radio network.[1] It allows users to make private or "group" voice calls between vehicle based mobile units anywhere within its coverage area. It is a Trunked radio system operating in the VHF-Low frequency range [2] and provides coverage in most of the main conurbations of the UK.

Ambitalk is owned by Maxxwave Ltd and operates using MPT1327 signalling with custom audio enhancements using Digital Signal Processing to give clearer audio quality than is normally available from MPT1327 or DMR/dPMR (which use the AMBE+2 codec).[3]

The UK Government has commissioned a UK Spectrum Usage and Demand report through the UK Spectrum Policy Forum (run by Department for Culture, Media and Sport). This report looks at all major communications solutions available across the UK and recognises that a significant number of two way radio users in the UK are now using Ambitalk as their preferred communications platform.[4]

Furthermore Ambitalk was awarded in 2015 the FCS Gerald David OBE award for Innovation in Business Radio. This award is given by the FCS, the UK communications trade body for the innovation that has been demonstrated by Ambitalk which sets it apart from other PAMR solutions. [5]

There is an in-depth look at the Ambitalk Network in the December 2015 edition of Land Mobile magazine in which it is clearly stated that the network has been designed with resilience in mind, using microwave links, batteries, generators and avoiding landline interconnections between sites.[6]

In February 2016 Maxxwave was presented the "International Critital Communications TETRA Award" for "Excellence in Radio Sites and Services", which includes the engineering within the Ambitalk Network. This was presented by Adrian Scrase, CTO of ETSI.[7][8]


History

The concept of Public Access radio networks is not new, with many networks such as GEC National One and Band Three Radio being launched in the UK in the 1980s. These closed around 2003 when Dolphin Telecom entered administration for the final time.[9][10]

Throughout the period of the 1980s to 2003 there had always existed smaller "regional" radio networks within the UK, with several of the larger networks operating a number of interconnected "regional" networks that formed a quasi-National operation. Wavelength and Fleetcomm, both now defunct are examples of these.[11][12]

Ambitalk is a reincarnation of the Maxxwave regional network originally covering Rugby, Coventry and Warwick in the Midlands and later adding additional transmitter stations to cover areas of London and Birmingham.

Around 2013 this regional radio network, previously powered by Zetron and Fylde MPT1327 controllers on Band III was redeveloped, with custom controllers designed by Maxxwave and was redeployed to lower frequency bands. This gave considerable cost savings, allowing the network to rapidly expand.[13]

Current state

From 2013 onwards Ambitalk rapidly expanded,[14][15] obtaining low cost national spectrum (due to the unpopular low frequency bands) and installing additional transmitter sites around the country.

In 2015 Ambitalk has concentrated on resilience and reliability, having replaced all Landline connections between transmitter sites with private Microwave and in-band links, giving it complete independence in case of any major catastrophe.

Ambitalk therefore is the only publicly accessible resilient wireless two-way communications network in the UK with other networks such as Airwave Solutions being closed, only available to select user groups. Furthermore it has a considerable amount of spare capacity, made available through its low frequency operation (rather than operating in congested UHF spectrum like Airwave) so therefore is far less likely to suffer congestion issues in case of major incidents.[16]

It has now become a clear market leader, having been awarded the prestigious Gerald David OBE Award in Innovation by the FCS (Federation of Communications Specialists), in recognition of the advancements it has made in the Two way radio arena. It is mentioned by name in numerous Ofcom documents with respect to the huge advances made in spectrum efficiency and has also been awarded the Critical Communications Award for Excellence in Radio sites and Services.

Low frequency bands

Ambitalk is unique not only because it is the UK's largest PAMR network but because it reverses the trend for modern wireless deployments to migrate to higher frequency bands.[5][17]

Higher frequency bands are preferred for rolling out wireless communications systems due to the lack of interference from atmospheric disturbances, smaller antennas and more manageable coverage characteristics, vital when planning a Cellular network

Low frequencies on the other hand are traditionally plagued by electronic interference from numerous sources and are prone to being unusable for weeks on end during summer months due to interference from foreign transmitters due to Sporadic E propagation thereby giving poor quality signals.[16]

Ambitalk has counteracted this Sporadic E interference by developing a Smart antenna array for low frequency bands. Such systems are normally only deployed in far higher frequency bands and the use of such a system in a low frequency band is somewhat unusual. However with these arrays it is possible to virtually eliminate interference from continental sources, thereby giving high availability of a level equal to or better than that possible with higher frequency bands.[16]

At a time when frequency spectrum is becoming increasingly scarce, with many of the traditional Business Radio frequency bands within the UK now being completely congested preventing any new two way radio deployments being made, the migration of users to these lower frequency bands is welcomed by the UK regulators such as Ofcom.[16][18]

See also

Ambitalk website:

References

  1. ↑ PMR News article on Ambitalk
  2. ↑ Ofcom presentation on low frequency spectrum used by Ambitalk
  3. ↑ Land Mobile Magazine 2015, Page 35/36
  4. ↑ UK Spectrum Usage and Demand - Second Edition - Summary Report. 16 December 2015
  5. 1 2 FCS Gerald David Award
  6. ↑
  7. ↑
  8. ↑ Peter Clemons - Post on Linkedin
  9. ↑ Website detailing older trunked radio systems in UK
  10. ↑ Dolphin enters administration
  11. ↑ Insolvent company link for Fleetcomm
  12. ↑ Archived Fleetcomm website
  13. ↑ Land Mobile article looking at FCS BR13, looking at Ambitalk
  14. ↑ Transmission1 internet forum with several independent members discussing receiving Ambitalk transmitters on their radio scanners
  15. ↑ Wireless magazine report on FCS BR13 event
  16. 1 2 3 4 Land Mobile December 2015 article Maxxwave: Set for Expansion
  17. ↑ S. F. Hasan, Emerging Trends in Communications Networks, Section 6.1 - 5G Expectations and Limitations. Springer, ISBN 978-3-319-07388-0
  18. ↑ Ofcom Business Radio Interest Group Meeting documenting encouraging users to lower frequency bands
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