Steven J. Crowley, P.E.
Comments are in on the FCC’s Notice of Proposed Rulemaking in WT Docket No. 10-4 to create new technical, operational, and coordination rules for wireless signal boosters in various services. These include the Commercial Mobile Radio Services (CMRS) that are covered by Part 22 (Cellular), Part 24 (Broadband PCS), and Part 27 (AWS & 700 MHz) of the FCC’s Rules. The services covered also include Part 90 (Land Mobile) and Part 95 (Personal Radio).
The due date for comments was July 25; reply comments are due August 24. (You can look at the comments and submit a reply through the first link above.) Comments and reply comments were originally due 30 days earlier; the FCC granted a request for deadline extension filed jointly by Verizon Wireless and Wilson Electronics (a booster vendor), who cited progress toward a solution that could benefit both manufacturers and carriers. They’ve submitted a joint proposal and I’ll spend most of this article looking at that.
As to the other comments, there are booster vendors naturally arguing for flexibility in design and operation. The in-building distributed antenna system folks are fine with boosters but don’t want any new rules to harm them. Public interest groups don’t want boosters tied to any one carrier, and want simple designs to keep the cost down. A company called Smart Booster brings concepts from dynamic spectrum access to boosters – intelligent units that know when and where to amplify or not. As noted above, the rulemaking proceeding also deals with Part 90 and Part 95 services; APCO addresses concerns about interference and unauthorized use in Part 90, and WCAI discusses various issues related to Part 90 and Part 95.
Most noteworthy, in my view, is the joint agreement among Verizon Wireless, its wireless engineering consultant V-COMM, and Wilson Electronics, that specifies requirements for the design, operation, and installation of boosters to help avoid harmful interference. This is a significant achievement for parties who are traditionally adversaries. The agreement provides for three categories of signal boosters: Carrier Installed Boosters, Certified Engineered and Operated Boosters, and Consumer Boosters. I’ll briefly discuss the first two, and spend some more time on the third.
The Carrier Installed Boosters would be installed by FCC licensees to operate exclusively on the licensees’ frequencies. The agreement doesn’t say much else about this, but there’s not much to say. Carriers have long been free to do pretty much what they want within the broad parameters of their license, and the agreement would not change this. They’re motivated to implement hardware that won’t interfere with themselves.
The Certified Engineered and Operated Boosters would be for large areas, such as campuses or large offices (CEO – get it?), and would require professional installation and close carrier coordination. The joint proposal provides a framework for these boosters, with technical standards yet to be developed. They would be operated under the wireless licensee’s authority.
Then we have the Consumer Boosters. Under the joint proposal, these could be purchased only by wireless service customers. They would basically be bi-directional RF amplifiers with antenna systems that transmit and receive signals using an outdoor antenna for transmission and reception to a CMRS base station, and an indoor (or in-vehicle) antenna (or direct connection to the mobile device). V-COMM provides a set of specifications for these. They’re technology neutral and intended to provide protection to all CMRS network technologies on all relevant bands. Among other things, the specifications include requirements for automatic gain control to protect against out-of-tolerance operation in instances of overload, anti-oscillation protection to limit power when the inside and outdoor antenna are too close, and limits on uplink and downlink EIRP of 1 Watt and 0.05 Watt, respectively. The uplink transmitter has to turn off if no signal is received from the mobile device in 15 minutes. Noise limits are specified.
Also part of the specifications, Consumer Boosters must be registered with the licensed carrier, either manually or through a Bluetooth connection. In the Bluetooth registration method, the booster operates as an extension to the mobile device and is controlled by it. The manual registration process provides for the customer to give their address, phone number, and other information to the carrier so it will know whom to contact if it suspects a particular booster is a source of interference; the customer would then be expected to turn it off.
An issue with the manual method is that it requires good faith on the part of the customer. Others commenting, including T-Mobile and CTIA, prefer that the booster be under some form of direct control by the licensee, so it can be turned off in the event of interference. Without direct control, the manual process is rather open ended. There isn’t much of an incentive for the customer to complete the registration process, registration information that is given will fall out of date, and boosters will be sold second-hand and no longer be linked to the original phone of record. WCAI goes into some of these issues in depth.
I’m surprised to see this manual approach in light of V-COMM’s position in the FCC’s experimental license proceeding (ET Docket No. 10-236), in which it opposed any experimentation by third parties in the CMRS bands due to interference concerns. As a carrier concerned about interference, I’d be less worried by Part 5 experiments than by many more boosters that are out of my direct control. But I’d also realize that many applications for boosters are now inside buildings, and deployments of Wi-Fi and femtocells will gradually displace boosters to some extent, while providing better performance. In addition, the operator may be able to tell which wireless device the malfunctioning booster is associated with and disable the device, thus disabling the booster indirectly once it times out.Still, I’m used to CMRS operators being able to control dozens of parameters on a cellphone, including those related to power control. It’s hard for me to not want control of one parameter on a booster – whether it’s on or off.