The choice of available radio frequencies is becoming increasingly limited. Both private and state organisations are trying to find solutions.

Radio Spectrum Shortage Prompts a Growing Number of Initiatives

In order to deal with the expected explosion of wireless traffic over the next few years, the French government recently decided to re-allocate the 700 MHz frequency bands away from radio and TV broadcasters to telecoms operators. This partnership which has been forced upon the two sectors is one of several solutions chosen which were discussed during the recent Spectrum & Innovation Conference, subtitled ‘Radio frequencies, a driver for economic growth’, held on 26-27 June at the Ministry of the Economy and Finance in Paris. However, although mobile telephony is a field that involves massive stakes for the future, not all governments are taking the same stance on the subject.

MIMO technology to the rescue?

In Mexico a decision has already been taken to allocate the 700 MHz frequency band to mobile operators, but this move goes hand in hand with a law forbidding the sale of smartphones without chips that can read televisual content. Professor Mérouane Debbah, holder of the Alcatel-Lucent chair at prestigious French graduate school of engineering Supélec, believes that “MIMO technology is a very restrictive solution, which demands greater coordination than the mere sale and purchase of spectrum, but which could supplement it.” Multiple-input and multiple output (MIMO) is a technique used in wireless networks; it uses multiple antennas at both the transmitter and receiver end in order to improve data throughput. “The major limitation to installing this type of antenna is however environmental,” underlines Professor Debbah. In fact the positioning of such relay antennas calls for a raft of administrative steps; they cannot be placed just anywhere in a public space.

In search of other solutions

At Alcatel-Lucent’s Bell Labs Open Days in June, a team led by Dr Vinod Kumar presented a prototype they have developed, which is capable of delivering high-speed broadband capacity on demand. Although the system does not solve the radio frequency allocation problem, it does nevertheless provide spontaneous on-site extra bandwidth. The researchers have developed experimental drone-mounted relay nodes, which when linked to a base station, enable coverage of a defined zone. In an ideal world, this solution would enable a rapid response during, for example music or sports events, when data traffic is at a maximum.


By Guillaume Parodi