The Case for the Unconnected Billions

Sending text messages, going on hour-long calls, or live-streaming videos are such an integral part of our lives that most of us take them for granted. And yet around 3 billion people live, today, in areas without access to basic infrastructure – be it remote islands in the Pacific, developing extra-urban areas, or isolated rural areas everywhere around the world.

Mobile communication can connect these people with one another and with technologies that can prove to be vital. Mobile data enables job seeking in wider area ranges, instantly accessing health care information in case of emergency or risk, or keeping farmers in line with market prices and trends.

In remote, unconnected markets, bringing voice and data coverage can be best achieved using GPRS, which provides wider coverage than 3G, and is easier to adapt to rural, remote, or low density areas. In such places, traditional cellular networks have the disadvantage of being economically counterproductive to deploy, and operators are unlikely to invest in hefty infrastructures that generate relatively little revenue from usage compared to the networks’ lifespan maintenance costs.

The YateBTS technology addresses these issues differently than most other approaches to mobile networks. 2.5G networks using SatSite and YateUCN are a simplified, flexible, and low-cost solution that can be adopted anywhere in the world.

Lightweight, low-power sites

SatSite is smaller than typical base stations which makes it easy to build lightweight cell sites that are especially profitable in higher density networks. SatSite’s low power requirements allow operators to plan self-sustaining mobile networks running on solar or wind energy, avoiding the use of costly power grids or diesel systems.

Bandwidth-efficient backhaul

Unlike traditional networks, a YateBTS/YateUCN mobile network allows bandwidth savings of up to 60%, by using the GTP protocol across the entire network.

bring_cov_2015-6-4_version1.2SatSite acts as a BTS/BSC communicating with the YateUCN core network over GTP, without using any additional network nodes, to simplify the network architecture and minimize the backhaul load. Data sessions in networks using YateBTS SatSite can be established either locally, by assigning the IP directly in the SatSite, or in the YateUCN core network, adapting to the constraints of each location.

SatSite unifies the BTS and the BSC from traditional radio access networks architecture, to eliminate the Abis radio interface used to direct traffic between the BTS and the BSC. In conventional cellular networks, the BSC handling all the communication between the core network and the devices leads to high costs and a substantial load on the network. SatSite base station can communicate with YateUCN over satellite, using GTP to replace the signalling interfaces normally used inside the radio access network and to/from the core network.

A satellite backhaul architecture is adapted particularly to sparse networks in areas with a low density populations, where cell sites are far from the core network; satellite allows operators to serve any location, and improve bandwidth performance for both voice and data services. Combined with the light design and an autonomous operation of the SatSite base station, backhaul over satellite makes YateBTS/YateUCN networks ideal for extending connectivity to uncovered areas.

What we talk about when we talk about coverage

There are a multitude of factors operators take into account before deploying their networks in order to provide us with the best possible coverage. Since the radio communication of mobile networks is peer-to-peer, the most significant aspect of coverage is that the device sees the mobile mast. To bring some clarity to what coverage means, and how to calculate it, we will introduce: the elements that influence coverage for both operators and their subscribers, coverage planning and our coverage and range estimation tool.

Coverage varies from cell site to cell site, and depends on the type of terrain, the equipment used, the type of buildings around the site, the radio frequency but also, very importantly, on the sensitivity and transmit efficiency of the subscriber’s equipment.

The coverage level also relies heavily on the antenna type or the amplifier power levels. The further you get from the cell site, the weaker the signal gets, as the ground clutter standing in the signal’s way increases. This makes coverage drop exponentially. ground_clutter_2015-3-5_draft1.2.1

Operators can increase the strength of the signal and the coverage, through higher power transmissions, taller antenna masts, a higher antenna gain etc. Antenna gain is, in fact, a crucial factor in getting a broader coverage, as it accounts for the losses and the directivity of an antenna. The relation between the antenna gain and the coverage is directly proportional, i.e. the higher the antenna gain, the more coverage the cell site will deliver.

Network planners use propagation models like Hata, Cost231 or Walfisch-Ikegami, to roughly calculate, in a quantitative manner, what can be expected in a specific environment. They also utilize more accurate tools that take into account the exact type of environment where their cell sites will be deployed, as the Radio Mobile RF propagation simulation software.

We created a tool that uses a very specific coverage propagation model, so do check out how it works with our SatSite. For more information on SatSite’s coverage area, click here.

For mobile subscribers, coverage depends on their devices’ capabilities, since they are not all the same. Also, the coverage level will not be the same if they use their device attached to a car kit, handheld or with an external antenna.

As an important note, always keep in mind that most times, coverage depends on both the device’s ability to “see” the antenna and the antenna’s capability to reach the device.