Ghanaian broadband powerline test
|July 22, 2005|
Africa’s first powerline implementation took a step nearer with a demonstration given in Ghana to a number of key players, including the Electricity Corporation of Ghana. Although there are now a number of implementations in the developed world, it remains a technology that has to prove itself. Cactel Communications (formerly Intell Solutions) demonstrated a small-scale installation and has plans for a much larger pilot. Russell Southwood spoke to Cactel Communications’ Andrew Boye.
In broad terms, there are two types of powerline solutions: one uses medium sub-station technology (33kv) and the other low-voltage sub-stations (11kv). In terms of a capital city like Accra, it has about 29 medium-voltage sub-stations and around 100 low-voltage sub-stations. Cactel’s Boye claims that the technology solution offered by its partners for deployment in medium-voltage sub-stations is 70% cheaper than anything offered for deployment in low-voltage sub-stations.
Deployment is carried out by switching off the sub-station and attaching an auxiliary cable from a coupling unit to a high-speed modem. This allows the bandwidth signal to pass through the same cable as the power it also carries. A medium-voltage sub-station has a 3 kilometre range but this can be extended by deploying what is called a Home Gateway which includes a modem and repeater to boost the signal strength.
In the test demonstration a medium-voltage sub-station was connected to the premises of the Graphic Corporation (publishers of the Daily Graphic) which has its own low-voltage sub-station. The test took place on the third floor of the building and powered up all the sockets as POPs. "It was a test designed to show that the system can work in an African environment."
Cactel says it was able to demonstrate internet connectivity, internet PC telephone, live streaming and the use of a surveillance camera. Boye told us: "We were able to use Skype to make calls to Europe and to make PC calls to Ghana Telecom and mobile subscribers on all networks in Ghana. We achieved low latency. We were also able to show video surveillance from a camera installed in a different part of the Graphic’s premises".
"We have the software to be be able to create a telephone network over IP within a building that will connect with analogue phones so that you won’t have to go to the expense of buying SIP phones."
The bandwidth was supplied by Africa Online using a 2 mbps link via a wireless link to the roof of the graphic building. According to Boye:"Speeds are dictated by the weakest link in the chain. Therefore in this instance the speeds achieved were limited by the link provided by the ISP. But the a medium to low-voltage link could give you as much as a 9 mbps speed. A chip capable of delivering 45 mbps can be used at this layer and a new one is being built that could give 200 mbps".
Although the test was attended by a number of people including Government, the regulator and Ghana Telecom, it was primarily designed to show the technology to the Electricity Corporation of Ghana. The company looks likely to be privatised and is looking to diversify in ways that will generate new income streams. Boye believes that "it would give them a more sophisticated network with higher value". The power utility company has also seen a demonstration from another supplier.
The aim had been to demonstrate particular applications specifically targeted at the utility company but the equipment did not arrive in time. However in the not too distant future it will show the Ghana’s power company a Remote Energy Management System. This is able to: read customers’ meters automatically; identify where power lines have gone down and where power is being drawn down illegally.
The most obvious question is whether bandwidth supply would be affected by the power outages that all too familiar to state power utility’s customers? Boye pointed out that the signal travelling through the electricity cable does not rely on power within the cable. Equipment used (the source of signal and modem) needs power but these can be powered from back-up sources.
So what are the capital equipment costs likely to be? On average one medium- voltage sub-station serves 10 low-voltage transformers which gives a potential customer base of approximately 2,000 customers. A medium-voltage sub-station modem costs between USD5-6000. The chip is produced by DS2, one of Cactel’s technology partners and another partner, EBA design the boxes themselves and get them built elsewhere.
If distances are greater than 3 kms, then there is a need a Home Gateway (a modem and repeater) which costs USD3,000. If you needed to reach 2,000 customers you might need two which would cost USD6,000. Each power point used needs an ICPE which can take up to three devices and these cost USD100 per power point.
Boye foresees the power company being bale to create its own supply ‘ring’:"You can ring together 10 medium-voltage sub-stations. It is the ubiquity that this approach will offer that makes powerline the key to last-mile solutions. It can also be used in a rural environment where the only requirement is access to electricity".
According to Boye 90% of the population in urban areas is passed by power supply lines and this falls to 50% in rural areas. As he points out:"All regional districts and their capitals are covered.
Cactel Communications has received encouraging signals from the regulator, the NCA and we believe that the Government is keen to see the company offer a larger pilot in rural areas using 5 of the UNDP-funded Community Information Centres.
In terms of how the company believes its business model would work, it would like to offer itself as a "carrier’s carrier" to whoever would like to buy bandwidth wholesale. But how would things work with the Electricity Corporation of Ghana?:"We may lease their network to provide bandwidth or we may engage in a joint venture".
The company believes that by the first quarter of 2006 it will have an agreement and arrangements in place to have a sizeable presence in the country.