By Sam Agona:
In February 2013, the Independent reported that Quality of Service (QoS) of Ugandan telecoms companies is sub-standard. Based on user experience, among the major telecoms companies, Airtel-Uganda has the poorest quality in terms of call success rate and coverage level, even after merging with former Warid Telecom which should had helped boost capacity. Later in June 2014, the Daily Monitor reported that mobile network subscribers in Uganda had dragged some telecoms in the country to High Court, Kampala due to "continued network failure and disruptions" among other bold reasons. It also reported that Uganda Communications Commission (UCC) had been sued for failing to ensure that desired quality had been met by the telecoms.
Network operators blamed the poor drive test results on methods used by UCC in determining QoS which involved sampling urban, peri-urban centers and conducting drive tests using keynote SIGOS Integrated Test Environment used for end-to-end testing.
The evident fact that remains is that network quality (speech quality, network availability and call rate success) is poor in Uganda. As user demand outstrips advances in technology and deployment, it is evident that telecoms operators are trying to manage traffic by increasing their voice and data pricing plans, among other strategies but these without other strategies cannot help.
Under the 3GPP the 3.5 GHz spectrum for mobile communications is being rolled out. Operators such as ROKE and Smile Telecoms are already beneficiaries using it for WiMAX. The frequency range 3.5 GHz (3400 – 3600) is a very important global spectrum for small cell enhancement. It is Microwave - Spectrum Access System (SAS) for the 3550-3650 MHz band (3.5 GHz band), as proposed in the 3.5 GHz NPRM which allows deployment of higher frequencies with lower coverage thus provision of more services over wireless networks. According to UCC, the long range spectrum in Uganda has been depleted by the current telecommunications service providers; this renders new entrants or provision of new services that need more spectrum almost impossible. According to the spectrum allocation table, the CDMA 450 MHz, GSM 900 – 1800 MHz and UMTS 1920 – 2165 ranges of frequency have all been assigned to providers thus a challenge for any increase in capacity by operators.
This purpose of this piece, therefore, is to show the need, dynamics and potential in adopting and using small coverage cell frequency in the 3.5/ 3.6 GHz or higher ranges to provide quality coverage in urban and peri-urban centers where data and voice usage is at maximum.
It is important for users to be involved because telecoms companies all over the world run as businesses and every business strives to reduce expenditure as much as possible to realize as much profit as possible. It is therefore important that telecoms users in Uganda and Africa at large know what service they expect and be active stakeholders in the industry.
The ultimate drivers for 3.5/3.6 GHz in Uganda include:
• Current excessive network shadow areas, low mobility and isolation which makes 42 band, with FDD attractive for outdoor setting in Uganda
• 3.5 GHz spectrum delivers high spectral efficiency for heavy usage areas (hot zones)
• The 200 MHz spectrum available is ideal as a dedicated large-bandwidth small cell band ideal on top of the macro cell coverage layer
• 3.5/3.6 spectrum offers the much desired isolation avoiding interference thus QoS and frequency reuse.
In Uganda, mobile technologies have evolved from EDGE, 3G some networks have deployed LTE using either TDD or FDD however the coverage is too low compared to the desired greater area of service and also face performance issues.
Earlier tests and deployments of 3.5/3.6 GHz cellular systems in Japan and US produced very encouraging results. This is being done at a time when network saturation is reaching its peak as smart devices have hugely penetrated the market, extreme appetite for advanced services and applications thus the projection that mobile data traffic will grow by thirty fold over the next few years and about 1,000 fold over the next ten years. The UMTS forum estimates that 880 MHz of additional spectrum will be needed to counter the growth in data usage in the next ten years.
Earlier pilot deployments in Japan which attracted 17 countries to Tokyo demonstrated 3.5 GHz deployment. Field drives were done in the 3.4 - 3.5 GHz band in densely populated parts of Tokyo, in densely populated rooftops, live measurements realized an average of 500 Mbit/s with peaks hitting 770 Mbit/s. These speeds were achieved with; beam-forming antennas, 4*4 MIMO, carrier aggregation, interference cancellation, coordinated multi-point (CMP), ultra-wideband remote radio units (RRUs) and cloud RAN with baseband units in a central office. Such a replica can be done perfectly by Ugandan telecoms that need small cell coverage to improve on speech quality and call routing success.
Conclusively, the highest concentration of mobile data traffic growth is in urban centers where operators ought to deploy small cells in the 3.5/3.6 GHz Spectrum range. Service providers with 700 - 1800 MHz spectrum range can use it as underlay network for basic coverage and 3.5 GHz to provide extra services. FDD has proved to work better than TDD in Uganda. Wireless networks have limitations; such changes can be financially costly for operators because BTS equipment manufactured by telecoms vendors such as Ericsson, Huawei, ZTE, Alcatel, for that spectrum should be procured and handsets in the frequency should be made available. The lower 700-900 MHz FDD frequency bands can work for 3 Kms and above and are suitable for rural or metropolitan settings. This will increase on coverage and boost capacity thus reducing the amounts of complaints to the regulator and reduce court cases against service providers in Uganda.
Huawei “Whitepaper on Spectrum”, February 2013
Special Research Report on "LTE TDD Services in the 3.5 GHz Bands, Opportunities and Challenges for LTE-Hi"