Tag Archives: 900 MHz

The FCC Opens the 900 MHz Band

The FCC voted in its recent open meeting to expand the use of 900 MHz spectrum. The order opens up the full 10 MHz available in the 900 MHz spectrum bands 896–901 and 935–940 MHz, for licensed broadband services. 900 MHz is an attractive band for users since the signals carry a long way and are good at penetrating buildings.

The licensed portion of the spectrum is not of interest to WISPs due to the small size of the channels, which won’t deliver the kinds of speeds expected by home broadband users. But the spectrum can easily support smartphone applications and is of interest to those wishing to deploy private 5G network.

This FCC change does impact the other bands of 900 MHz spectrum. For example, there are numerous uses allowed for the spectrum between 902 and 928 MHz, including ham radio, FM radio repeaters, alarm and security camera systems, video surveillance for law enforcement missions, and transmission of infrared scanner imagery during overflights of disaster areas. Some of these uses are restricted in Texas and New Mexico since this spectrum is also used to monitor the border.

The primary users of the expanded-use bands will be electric, gas, and water utilities that have been using the spectrum for automated meter reading and other network monitoring devices. The purpose of the FCC’s change is to provide more bandwidth and expanded capacity to utilities. The FCC order predicts that the changes to the spectrum usage will promote better smart metering, grid modernization, and network security and resilience. Under the former rules, transmissions in the band were restricted to 5 MHz licenses, which limited the ability for utilities to launch private 5G and LTE networks.

The new order provides different options for a current license holder to:

  • Continue to use the legacy configuration of 20 wideband channels and 200 narrowband channels.
  • Operate two paired 3 MHz channels and two segments of the remaining 4 MHz of spectrum to operate 159 narrowband channels.
  • Operate two paired 5 MHz channels to deploy more broadband use cases.

This change largely benefits Anterix. The company purchased a nationwide license for 6 MHz of the spectrum from Sprint in 2014. Anterix has been selling and leasing that spectrum to utilities to create private wireless networks. This new order gives the company the use of all 10 MHz of the spectrum.

One of the most interesting aspects of the new order is that it anticipates that the spectrum will be made available to others through voluntary negotiations and market-based transactions. The Anterix spectrum today is largely deployed on a county-by-county basis, and this order opens the door for entities other than utilities to license the spectrum to create local private 5G networks. This could be used by corporations or local governments looking for a private and secure wireless network outside of the public cellular networks.

I recently noted how the public cellular networks crashed in Western North Carolina after Hurricane Helene. While a number of cell sites sustained physical damage, many were still operational, but still failed since the backhaul fiber lines feeding the region were damaged or destroyed. While the lack of cell signal was a major inconvenience for the public, it was a crushing blow to first responders who found themselves unable to communicate. A private in-county 5G network for first responders using 900 MHz could have continued to work locally on the functional cell towers. This would have greatly benefited the search and rescue effort and the overall coordination of first responder resources.

It will take a while to see if this is a giveaway to Anterix or if this will really open up new opportunities for first responders and other local private wireless network providers.

FCC Takes a New Look at 900 MHz

The FCC continues its examination of the best use of spectrum and released a Notice of Inquiry on August 4 looking at the 900 MHz band of spectrum. They want to know if there is some better way to use the spectrum block. They are specifically looking at the spectrum between 896–901 MHz and 935-940 MHz.

The FCC first looked at this frequency in 1986 and the world has changed drastically since then. The frequency is currently divided into 399 narrowband channels grouped into 10-channel blocks. This licensed use of the spectrum varies by MTA (Major Trading Area), where channels have been allocated according to local demand from commercial users.

One of the more common uses of the spectrum is for SMR service (Specialized Mobile Radio), which is the frequency that’s been used in taxis and other vehicle fleets for many years. The other use is more commonly referred to as B/ILT purposes (Business/Industrial Land Transportation). This supports radios in work fleets, and is used widely to monitor and control equipment (such as monitoring water pumps in a municipal water system). The frequency was also widely used historically for public safety / police networks using push-button walkie-talkies (although cellphones have largely taken over that function).

The FCC currently identifies 2,700 sites used by 500 licensees in the country that are still using B/ILT radios and technologies. These uses include security at nuclear power plants including public alert notifications, flood warning systems, smart grid monitoring for electric networks, and for monitoring petroleum refineries and natural gas distribution systems.

But we live in a bandwidth hungry world. One of the characteristics of this spectrum is that it’s largely local in nature (good for distances of up to a few miles, at most). When mapping the current uses of the frequency it’s clear that there are large portions of the country where the spectrum is not being used. And this has prompted the FCC to ask if there is a better use of the spectrum.

Typically the FCC always finds ways to accommodate existing users and regardless of any changes made it’s unlikely that they are going to cut off use of the spectrum in nuclear plants, electric grids and water systems. But to a large degree the spectrum is being underutilized. Many of the older uses of the spectrum such as walkie-talkies and push-to-talk radios have been supplanted by newer technologies using other spectrum. With that said, there are still some places where the old radios of this type are still in use.

The FCC’s action was prompted by a joint proposal by the Enterprise Wireless Alliance (EWA) and Pacific DataVision (PDV). This petition asks for the frequency to be realigned into three 3 MHz bands that can be used for wireless broadband and two 2 MHz bands that could be used to continue to support the current narrowband uses of the spectrum. They propose that the broadband channels be auctioned to a single user in each BTA but that the narrowband uses continue to be licensed upon request in the same manner as today.

This docket is a perfect example of the complexities that the FCC always has deal with in changing the way that we use spectrum. The big question that has to always be addressed by the FCC is what to do with existing users of the spectrum. Any new allocation plan is going to cause many existing users to relocate their spectrum within the 900 MHz block or to spectrum elsewhere. And it’s generally been the practice of the FCC to make new users of spectrum pay to relocate older uses of spectrum that must be moved. And so the FCC must make a judgement call about whether it makes monetary sense to force relocation.

The FCC also has to always deal with technical issues like interference. Changing the way the spectrum will be used from numerous narrowband channels to a few wideband channels is going to change the interference patterns with other nearby spectrum. And so the FCC must make a determination of the likelihood of a spectrum change not causing more problems than it solves.

This particular band is probably one of the simpler such tasks the FCC can tackle. While the users of the spectrum perform critical tasks with the current spectrum, there is not an unmanageable number of current users and there are also large swaths of the US that have no use at all. But still, the FCC does not want to interfere with the performance at nuclear plants, petroleum refineries or electric grids.

For anybody that wants to read more about how the FCC looks at spectrum, here is the FCC Docket 17-200. The first thing you will immediately notice is that this document, like most FCC documents dealing with wireless spectrum, is probably amongst the most jargon-heavy documents produced by the FCC. But when talking about spectrum the jargon is useful because the needed discussions must be precise. But it is a good primer on the complications involved in changing the way we use spectrum. There has been a recent clamor from the Congress to free up more spectrum for cellular broadband, but this docket is a good example of how complex of an undertaking that can be.