With Mobile World Congress approaching, it is worth taking note that at CableLabs, wireless technology represents the largest area of research. Of the approximately 58 MSO members worldwide, 24 are already mobile network operators. WiFi is the largest carrier of mobile data, and the majority of WiFi sits on the cable network, said CableLabs President and CEO Phil McKinney.
"Cable is the largest transport network for wireless data in the world. It is part of the network today and always has been," McKinney said. "Wireless today is core to the cable industry because customers don't want to leave their broadband when they walk out the front door. They want reach and access to broadband no matter where they are."
One of the wireless projects engaging CableLabs involves the 3.5 GHz band. What this means for cable operators is the ability to use LTE technology without being a mobile operator with its own spectrum.
"Cable can use LTE as a technology as small as cells deployed in homes and offices," said Peter Smyth, CableLabs VP of wireless. This will enable them to talk not only with WiFi devices, but also with LTE devices.
CableLabs also is participating in the MulteFire Alliance, which is working on 3GPP License Assisted LTE Access. The gist is that this uses listen-before-talk etiquette like WiFi. The difference is that the control signaling will be in unlicensed spectrum. Cable operators will be able to access LTE technology in the 5 GHz band, which is primarily used for WiFi today, McKinney said.
In order to use 3.5 GHz, devices need to have a built-in radio, which Smyth anticipates will happen in the next two years. Since MulteFire already supports WiFi, devices already have the necessary radios. However, silicon makers will need to incorporate the MulteFire technology into chipsets. The 3.5 GHz opportunity supports native LTE in a way it already is supported in networks.
"My view is that 3.5 GHz will happen first and support native (LTE) technology. When that is successful and there are tens of millions of access points across the U.S., then (we will use) MulteFire as another means to handle the density of the access points elegantly," Smyth said.
A sidebar to the 3.5 GHz story, however, is that certain radar systems on U.S. Navy ships utilize the band. Currently, there is an exclusion zone that reaches 50-70 km off the U.S. coasts. CableLabs is working with policy makers to reduce this exclusion band and also to develop detection technology to determine when and where the radar is being used.
A Navy carrier using the radar would only be using one or two channels out of 15, even if it is in port, but it is not always the same one or two, Smyth said. "We need a dynamic system to detect the arrival of a carrier system and to tell people not to use those two (channels) and cause interference."
The detection system that would allow spectrum sharing in this way would require sensors every 50 km or so along the coasts. "Cable is in a great position to build these (detection) networks because they have poles," Smyth said.