Performance characterization of e-band links for wireless back-haul in broadband networks: the case for Kenya.

Abstract

The demand for high data speeds by users of mobile and fixed data services, telecom operators, data service providers and heavy data application institutions has posed a huge challenge of optimum backhaul solutions. To this end, the commercial viability for 71-76/81-86 GHz frequency band commonly referred to as E-band spectrum has attracted a lot of research for the last decade in order to find economic wireless gigabit connectivity that can complement optical fiber cable. Several countries have so far promoted the use of E-band by proposing the licensing model and licensing fee with USA and Australia cited as the countries that have implemented E-band links. Since weather statistics vary from place to place, ITU-R has recommended prediction methods for different regions based on weather statistics for link propagation design. These prediction methods are based on specific climatic and topographical conditions within radio administration territories. Given that Kenya has its own whether patterns it’s necessary to carry out practical experiment to validate the literature with a view to opening up E-band for use in Kenya. This research has analyzed the usefulness of E-band point-to-point microwave link in providing wireless backhaul capacities comparable to that of fiber optic cable. In partnership with Safaricom Ltd as the sponsor, practical experiments have been utilized in this study with transceiver equipment from two suppliers: NEC Africa (PTY) Limited and Aviat Networks. In particular, microwave links that utilize the E-band frequencies were set up in three different cities in Kenya i.e. Nairobi (Latitude 01 19 10.41 S, Longitude 036 53 30.95 E), Mombasa (Latitude 04 01 24.10 S, Longitude 039 37 35.10 E) and Kisumu (Latitude 00 05 45.80 S, Longitude 034 45 20.79 E) and validated the acceptable propagation and data performance of E-band links for distances within and above the values given in the existing literature. Daily occurrences of signal losses were compared with the rainfall pattern, and this has been used to further validate the practicality of the experiments. From the experiment it can be concluded that the typical range for E-band should be up to 3km for link availability of 99.999%. It was also noted that E-band link can operate up to 6km under clear whether conditions. Based on the results, it is therefore possible to use E-band link for backhaul solution in broadband networks. The results of this case study will provide practical planning data and information on the acceptable link range, frequency planning, propagation and performance of E-band links.