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C-band and CBRS consternation could be great IoT opportunity

At its heart, the IoT relies on networks to carry its data from point to point, getting those valuable data packets back to applications that can turn them into some sort of valuable business outcome. As such, any potential new networking technology is sure to prick up our ears, but MWC was a mixed bag when it came to enthusiasm for the new opportunities – based on our conversations.

There were concerns that the new spectrum opportunity could simply be swallowed up by the incumbent MNOs, leaving the smaller players and their innovative IoT approaches squeezed out of the market – especially if expensive usage licenses are lobbied for. Crucially, the two bands lie within the 2.4GHz and 5.8GHz ISM bands, meaning that they are much more likely to be adopted by the mass-market consumer devices that can provide a solid basis for future IoT hardware.

Much of the componentry in the IoT world is caught in a chicken-or-egg state, where network investments hold out for a critical mass of devices, and so a more ‘common’ radio protocol gives a device a better chance of catching a network operator’s interest. So far, the ISM bands have proven best placed, but the new 3.5-4.2GHz options could emerge as another option.

However, it is not yet clear whether the FCC is going to be promoting newer 5G-type projects, or simply opening up the new spectrum options to existing LTE and WiFi technologies. With three tiers (Incumbent, Priority Access, General Availability) there is a danger that any freed up spectrum will be seized upon by the MNOs, who have much deeper pockets than the rest of the wireless industry, who will then use their exclusive licenses to better serve smartphones – rather than push for more innovative applications, such as smart city, automotive, industrial, or utility.

Citizens Broadband Radio Service (CBRS), not to be confused with the Citizen’s Band in the 27MHz band, is found in the 3.5GHz range of the FCC regulations. In 2010, the regulator announced that it would be attempting to open more spectrum, as part of the National Broadband Plan, and later in 2016, clarified that it would be creating the CBRS ‘innovation band’ in the 3550-3700MHz range.

Effectively ousting previous satellite and military users of that 150MHz of spectrum, although they are protected by some usage regulations, the new CBRS band was intended to boost broadband services – including both WiFi, LTE, and fixed-wireless delivered broadband. In theory, any device using the CBRS band has to use a Spectrum Access System (SAS – effectively a system of commercial databases that some have complained can be quite inaccurate), to ensure that it won’t interfere with those ‘Incumbent’ users.

But in areas where that spectrum is free to use, private LTE networks have become one of the most hotly anticipated use cases, with fixed-wireless access networks usually voiced in quick succession. Currently, a user can pay a fee to use a dedicated 10MHz block of this spectrum in a limited geographic area for three years, but there is a 7-concurrent-block limit – so that someone couldn’t just buy out the entire band. If there are no Incumbent or Priority users on air, then the band is free to use – called General Authorized Access.

Notably, both of these usages threaten the incumbent MNOs, as they can bypass the previous LTE gatekeepers – although this does cover LTE Band 42 (3.4-3.6GHz) and Band 43 (3.6-3.8GHz), which are used in Japan.

The C-Band sits above the CBRS band, used by satellite networks, broadly spanning 3.7-8GHz, typically using 3.7-4.2GHz for downlinks and 5.9-6.4GHz for uplinks. At MWC, FCC Chairman Ajit Pai confirmed that the FCC was looking at implementing a plan backed by Intel, Intelsat, and SES, which would see the satellite band opened up for terrestrial (ground-based) networks to use.

Now, SES and Intelsat have commercial interests at heart here. Collectively, they own around 90% of that band in the US (with Eutelsat and Telesat being the other 10%), and will stand to gain from selling off chunks of that ownership to companies looking to use the spectrum on the ground.

However, neither have actively said they planned on selling off spectrum, rather that they would open it for ‘joint use’ – but shareholders will gut them if there isn’t a promise of commercial returns somewhere. This might be a response to Google’s claim that a third of the FCC-registered C-Band installations are not actually being used – and the MNOs would love to have seized on that as leverage to excise the satellite operators from the band.

When first proposed, Intelsat wanted to make the full 500MHz available for purchase, but the current proposal only concerns 100MHz – the price of SES’ backing, perhaps. It seems apparent that the two would have to migrate some of their existing customers out of the C-Band, because currently mobile and satellite signals in proximity of each other cause interference. A C-Band Satellite Consortium would be set up to ensure that the new uses won’t interfere with the existing C-Band deployments.

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