Ofcom Offers More 5.8GHz Spectrum to Speed Boost Wireless Broadband ISPs

The UK telecoms regulator has today proposed to free up an extra 20MHz notch of radio spectrum in the 5.8GHz band, which is currently used for road tolling systems, so that it can be harnessed to boost the speed of existing outdoor Broadband Fixed Wireless Access (BFWA) providers.

Ofcom notes that 5725-5850MHz band is popular for BFWA services and around 12,000 sites are registered under their related light licensing scheme (400 BFWA licences), although this excludes a 20MHz notch (between 5795 and 5815MHz) that remains reserved for use by road tolling systems (mostly used in the EU).

However road tolling makes light use of these frequencies in the United Kingdom and so the regulator believes that the notch is “no longer a proportionate approach to managing coexistence in these frequencies.” BFWA also shares the 5.8GHz band with other radio systems including amateur, FSS uplinks, PMSE, radars, short range devices (SRDs) and industrial, scientific and medical (ISM) applications, but Ofcom doesn’t expect their proposal to “impact coexistence with these.”

Apparently there are just 7 road tolling systems using 5.8GHz in the United Kingdom and they include the Dartford Crossing, Humber Bridge, M6 Toll, Mersey Tunnels, Severn Crossing, Tamar Bridge / Torpoint Ferry and Tyne Tunnels (Severn Crossing’s tolls are due to be removed in 2018). In other words, there’s no reason why Ofcom can’t free up the extra 20MHz and avoid interference concerns through the existing application process.

The move could offer a nice speed boost to 5.8GHz networks by opening up more channels. For example, there are currently four channels with 20MHz bandwidth and just one with 40MHz bandwidth. However by removing the 20MHz notch it would actually be possible for ISPs to accommodate six 20MHz channels and three 40MHz channels.

Ofcom claims one ISP informed them that they can currently deliver 70Mbps at 7km distance, but that this could be doubled to 140Mbps at 5km without the notch (this capacity would normally be shared among premises, so the final end user would see lower speeds). The regulator plans to consult on these changes until 21st September 2017.

The measures follow on from another recent tweak to the 5.8GHz band, which made an additional 125MHz of radio spectrum available to indoor WiFi networks (here). Today’s proposal may help to placate some of the BFWA interference concerns that were raised about the WiFi change.