In a world of ever more sophisticated smartphones, it’s easy to overlook the fact that half of the world rely on GSM for their cellular service. Rather than dying out, in some regions 2G has a long life ahead of it. That’s why Parallel Wireless has added 2G to its solution, primarily to address strong market demand in developing countries.
2G dominates until 2018
As you can see from the chart below (source GSMA Intelligence), the transition towards 4G still has some years ahead of it. The largest user base today is still 2G (39% market share) giving way to 4G next year which will see the bulk of new investment. 3G has peaked and will start to tail off from 2020. 5G won’t have any significant impact for at least five years.
Most of this GSM use relates to countries with much lower ARPU. It’s not just the cost of the network itself, but handsets – a useful second-hand GSM featurephone can be bought for a few dollars. The battery life is measured in weeks, not hours. Voice is more useful in regions with low literacy levels. For roaming traffic, GSM provides the lowest common denominator because it’s present in almost every phone and almost every network worldwide.
Many business users in developing countries will have two phones, the second being a GSM feature phone because of extended battery life and primarily used for voice calls.
This means that 40% of cellular connections in developing regions will still be running on 2G in 2020, compared to less than 10% in developed regions. India and Sub-Saharan Africa account for 42% of the world’s unconnected, with more than 60% of their respective populations not yet on the Internet. (Source GSM Intelligence).
4G growth for the long term
You may think that this would best be solved by leapfrogging directly to 4G.
The “poster child” of a greenfield 4G deployment has been Reliance Jio in India which invested over $20 billion in a brand new 4G only network. Low cost 4G smartphones combined with tens of thousands of basestations now support over 120 million subscribers. The simplicity of using a single radio technology helps offset the higher costs of handsets.
However, the most common issues reported relate to battery life and difficulties with voice service. There’s even talk of a merger with Reliance Telecom which could combine their service to include 2G and/or 3G in the future.
2G today, 4G tomorrow
The situation seems to be that 4G is not quite yet ready to be fully standalone solution for developing markets today. Low cost GSM is still in demand to provide a basic featurephone service in low ARPU regions, such as Africa, South America and parts of Asia.
Today’s investments need to cater for the transition to 4G in the next few years. The price of 4G smartphones will undoubtedly continue to drop, secondhand units will become more widespread, and more widespread access to power will alleviate battery life. With the majority of the world’s population relying on mobile devices to access the Internet rather than laptops or desktops, 4G will narrow the digital divide.
VoLTE has not been a great success, with many incompatibilities. Not all operators will ever deploy it, relying on fallback to 3G or 2G for voice calls. Roaming traffic is also likely to benefit from widespread 2G availability.
This background explains why network operators in developing regions are looking for a solution that fits those needs:
- Low cost, simple to deploy and operate
- Low power consumption
- GSM service for wide area coverage
- Easily upgradeable to LTE as and when required
Parallel Wireless adds GSM to their RAN solution
We’ve previously reported on how Parallel Wireless have developed their own hardware platform using the latest low cost small cell chipsets. They’ve combined that with some of the highest RF power amplifiers to achieve a total maximum 80W from a single compact unit called the CWS (Converged Wireless System).
It’s effectively a Software Downloadable Radio, capable of “Any G”. Their initial product was 4G later followed by 3G. Much hard work in the past year has led to their adding 2G capabilities, again all running on the same hardware platform.
It benefits from being developed from the outset using the latest technology, making full use of software techniques such as virtualisation and self-configuration. They’ve proved that no specialist technical knowledge is required for successful deployment – for example earlier this year, Ice Wireless sent the kit for installation by villagers in Northern Canada.
Energy efficiency is important in areas without connection to a national grid. A mix of solar panels, wind turbine and batteries can provide a reliable power source avoiding the need for a generator (and the high cost of refuelling it).
Several backhaul options are available, relaying from a nearby macrocell donor site, through microwave point-to-point links, direct wireline feed or even via satellite. We’ve reported on those being used in remote areas of West Wales earlier this year.
The key point is that operators in these regions can now invest in 2G equipment today, safe in the knowledge that they can upgrade to 4G in the future without high costs or timescales. It’s also possible to run both 2G and 4G simultaneously at different frequencies.
Parallel Wireless anticipates significant demand, having had good traction with operators in these regions. Although 3G functionality is also available, they tell me that 2G+4G is viewed as the winning combination.
The standard GSM BSC functions together with A and Gb interfaces have been added to the central HetNet Gateway, which serves 2G/3G and 4G. System provisioning and management use the same framework for all technologies.
The CWS basestation can support 4 GSM TRXs (200kHz channels). With each channel hosting 8 active voice calls, this provides 31 concurrent calls at full or enhanced rate. Support for the GSM half-rate codec expands that to 62. (One timeslot is required for the pilot broadcast signal).
SMS text and GPRS data is also supported, together with all the usual security/encryption, mobility/handover and compatibility features we take for granted from cellular services today.
The small form factor belies the total RF power output of up to 80W in total, split between the four active carriers.
You can watch a 7 minute video where Rajesh Mishra, President and CTO of Parallel Wireless, walks through the product features and capabilities.
Example deployment scenarios
The tower site below is a simple chain link fence enclosure with gravel/weed free floor hosting a solar panel, antenna tower and satellite VSAT dish. The battery pack underneath the solar panel provides up to 3 days autonomy.
A smaller mast can be used and the solar panels fitted to existing buildings, avoiding the need for additional mounting poles.
The small size of the unit makes it feasible to mount on the antenna pole, including existing telegraph poles, or onto existing buildings with little or no specialist training.