The experience would be like roaming between cell networks and it could send a lot more mobile traffic off the scarce cellular frequencies, helping mobile operators to get by longer with the spectrum they already own. But carriers are expected to adopt the new roaming technology slowly. Consumers should note that unlike the access offered now on carrier-owned hotspots, Wi-Fi roaming may not always be free for subscribers.
Reducing the amount of data on the network
No matter what frequencies are used to carry mobile data, less traffic means less spectrum is needed. Data compression is a time-honored way of cutting files down, but it has its limits as a solution to the wireless crunch, according to Rajat Roy, a senior product line manager at Broadcom. To start with, the biggest files, such as video, audio and images, are already compressed using standard protocols such as JPEG and MPEG. For other types of files, the industry is still trying to settle on a common standard so mobile devices will have the software to decompress what's been compressed in the network.
However, Broadcom has targeted one type of traffic that doesn't make for huge files but is often inefficient. The company builds technology into its wireless base-station chips that can compress the header fields of VOIP (voice over Internet Protocol) packets. Though voice doesn't take up much bandwidth, the packet headers containing routing and other information are sometimes twice the size of the payload itself, Roy said. Compressing the headers reduces the load on the network.
There are at least two ways in which caching could help reduce the need for spectrum. One is time-shifting traffic to reduce peak demand. The growing amount of storage capacity on devices and in removable flash cards could allow users to download large files such as video automatically during off hours, said Tolaga Research analyst Phil Marshall. Users who signed up to have that content sent could then watch it later on the device. Security and digital rights management are possible barriers to adopting this technique, Marshall said.
Broadcom has another caching idea: The company equips its cellular base station processors to identify and cache multimedia content while sending it out to client devices. The idea is to keep filling the "time slots" on a wireless pipe that the network allocates for the file transfer. Letting those slots go unfilled wastes network capacity. Broadcom's chips can store enough packets of a file or a multimedia stream in memory so that the base station can pack as much data as possible into every time slot devoted to that application, Roy said.
10. Reducing signaling traffic