Spectrum Refarming in LTE Network Planning the Case of Addis Ababa
No Thumbnail Available
Date
2016-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The deployment of Long Term Evolution (LTE) provides a better way to meet the increasing user demand for high rate mobile data. However, obtaining spectrum resource needed and deployment band selection are among the challenges to meet the demand. Spectrum already in possession by older technologies can be divided and granted to deploy new technologies. Such a technique of clearing frequencies from low-value (by economic and/or social criteria) and reassignment to high-value applications is called Spectrum Refarming.
In the case of Ethiopia, a 20 MHz bandwidth is statically refarmed to LTE from Global System for Mobile Communications (GSM) 1800 band, which has propagation advantages over the main stream 2600 MHz band while maintaining the remaining spectrum for legacy users. But static spectrum refarming (SSR) does not respond to the changing traffic conditions and the refarmed spectrum remains underutilized.
In this thesis, dynamic spectrum refarming (DSR) approach is proposed for possible use in Ethiopia’s LTE deployment. The refarming intends to use LTE’s flexible bandwidth deployment opportunity to refarm the available spectrum and insure smooth transition from GSM to LTE, which eventually be the case. To this end, a case study area of around Gerji area is considered in Addis Ababa containing 5 GSM base stations and still co–sited with LTE.
Different user equipment distribution scenarios are generated for 200 mobile users in the covered area via simulation and results for the cases of static and dynamic spectral allocations are obtained. The results show that DSR can save 42 % of spectrum refarmed by SSR and possibly reallocates the physical resource blocks (PRBs) for about 155 GSM users in particular need that would rather be wasted in vain. Beside the efficient spectrum usage that can be achieved by employing dynamic spectrum refarming scheme, the aggregate throughput of the network is improved by 7.5 % for uniform User Equipment (UE) distribution case while 13.4 % improvement is achieved in the non-uniform UE distribution case as compared with static refarming.
Key Words: LTE; GSM; Static Spectrum Refarming; Dynamic Spectrum Refarming;
Description
Keywords
LTE, GSM, Static Spectrum Refarming, Dynamic Spectrum Refarming