Technology has offered an alternative means of keeping Kenya moving, connected and informed in the midst of disruption occasioned by the COVID-19 pandemic.
Sustained investment in boosting capacity of our state-of-the-art network infrastructure over the years puts us in good stead to keep the country connected and to empower a digital lifestyle.
Here is a glimpse of how Safaricom’s vast network comes together to keep us connected.
The Converged Network
The visible parts of the network are masts (also known as base stations) that are scattered across the country. It is to these masts that voice calls, SMS, internet data and USSD initiated by subscribers are channeled. There are 5,300 masts located across the country in intervals of between 1 and 20 kilometres for good 2G, 3G, and 4G coverage.
When a customer initiates communication (a call, SMS, data, USSD or M-PESA transaction), it is picked by the closest mast.
This is channeled to a Controller that collects traffic from several sites within an area and also ensures that service remains uninterrupted even when a user is moving.
The Controller transmits traffic through a high-speed transport network that can handle up to 400 Gigabits per second to the Switching Centre.
It is at the Switching Center that intelligence occurs, sorting out traffic into calls, SMS and internet data, before respective servers and switches deliver it to the intended destination. The Switching Center has an in-built billing system that first checks if the user has adequate resources before completing the communication.
M-PESA rides on the same network. It follows the same path utilized by the SMS until the point it gets to the Switching Center, where SMS servers talk to the M-PESA system to complete the transaction. M-PESA can now also be accessed over our mobile data network through the Safaricom Application.
The same happens for USSD, which offers a means for interacting with the network by sending commands. In this case, when the command gets to the Switching Centre, it nudges the gateway to trigger a response from the network or any of the partners offering the service, in the form of a prompt.
All this is made possible by the SIM card inside the phone, which gives a user identity on the network. The SIM card is identified and authenticated by a customer database in the core of the network.
The vast network is designed to deliver a good experience to all users by situating sites across the country. The 2G network covers 95 per cent of the population, while 3G and 4G reach more than 87 percent of the population. Controller and Switching Centres are aggregated in the Data Centres that hold the core of the network and are located in Nairobi, Mombasa, Kisumu, Nakuru, Thika and other satellite towns. Through these centres, we are able to deliver services closest to the customers for a good experience on the network.
This network is deployed with redundancies to ensure backup for the system to avoid losing service in case of failure.
The Switching Centre has controls to ensure safety and security of the physical installations and the systems to protect subscribers’ data, in compliance with the Data Protection Act.
Home internet is delivered by the more than 6,700 kilometres of fibre optic cable that we have deployed countrywide, particularly in urban areas.
Signals from several houses within a locality are aggregated into a central office and transported to an Optical Live Terminal (OLT). It is here that the signals are aggregated and directed to the network gateway (BNG).
At the gateway the signal acquires an IP address (this is like a combination of your house number, block name and estate name) that gives it identity within the network and queries whether a user account can connect and what services they can access. This is where service differentiation happens, based on the package that the user signed up for.
The optical signal from the fibre cable is delivered to a terminal set up inside the house which converts into a WiFi signal to provide internet connectivity.
Currently, there has been a shift in traffic from offices to residential areas as many people work from home. This has been mitigated by vast distribution of sites that has made it possible to cater for the additional load and to support the shift in network traffic. We are continuously and proactively increasing capacity on access links closest to customers to support the additional traffic and keep utilization below limits required for a good experience.
Partnership with major content providers, such as Google, Facebook, Netflix, Akamai, Amazon, Microsoft among others, make it is possible to contain up to 60 percent of the traffic within the country for a superior quality experience for mobile data and home internet users.
For example, if thousands of viewers are searching a new popular video, a copy of that video is stored in Nairobi or Mombasa. This then means that every new viewer does not have to wait for every megabyte to travel the 14,000 kilometres to and from London. Instead it travels at most a few hundred kilometres at almost 300,000 kilometres per second – the speed of light and the speed of a signal in a fibre optic cable.
We also have a traffic accelerator in our network to offer the best quality of experience. It creates a smooth and superior video experience that is adaptive to the various network technologies and conditions and is aware of device capability.
For the internet, robust security systems are in place to ensure that customers are well protected from any attacks.
We have a robust 24 Hour Network operations center to monitor and ensure that the network operates free of faults and incidents.