Radio waves have no respect for man-made constructs such as borders between nation- states. The inevitable result is overspill of signal in all areas of the spectrum between one nation-state and another. The International Telecommunications Union has developed recommendations for management of this overspill and yet uncertainty still remains. This uncertainty comes from the latitude that exists for nation-states to reach their own bi-lateral or multi-lateral agreements to fit local conditions. And so it was in the Middle East where overspill of 2G and 3G mobile services became the subject of a recent comprehensive study by InterConnect Communications.
There are three reasons for wanting to control overspill of signal. The first is interference between networks. To effect control of this, techniques such as preferential frequencies
and codes need to be employed governing assignments to stations within 100km of the border. The second is the inadvertent roaming of citizens of one nation- state on foreign networks. Mostly they don’t realise and only find that they have roamed when they see their high phone bill. The third is the issue of national security. If there is extensive coverage of a nation-state by a foreign cellular network then this can be used to escape the prying eyes of local security agencies for those involved in criminal activities at or near the border.
InterConnect consultants approached the project using both modelling and measurement to determine the degree of breach of a current 2G bi-lateral agreement and to re-craft this and postulate a 3G agreement that would be practical for cellular operators to meet whilst controlling the problem. Commented John Berry, Director of Spectrum Services at InterConnect “it’s too easy to assume that either the operators will sort it out or that the ITU or ECC recommendations alone will control all issues. This is rarely so and local agreements are essential.” As Jan Verduijn, the InterConnect survey project manager, commented, “This was an adventure of a lifetime. It’s not often that spectrum engineers get the chance to drive 2,500km of beautiful borderlands in search of rogue signals!”