If Lesotho were to benefit from the envisaged and much hyped digital migration, using satellites rather than terrestrial towers would be the wisest option. Lesotho’s legendary rugged and mountainous landscape, while good for tourism, may not be as good for terrestrial television.
That is according to a research by Mr. Itumeleng Potsanyane. He is a fifth year Electronics Engineering student at the National University of Lesotho (NUL).
In his research, Mr Potsanyane found out that the choice of tower- dependent form of digital television in Lesotho at an estimated M500 million is rather questionable for a variety of reasons. These include the form of settlement most Basotho chose. Lesotho’s rugged mountainous landscape, and the limitations of tower based communication. These factors may work in unison to deny many Basotho access to the benefits of digital migration.
While digital migration has become a household phrase in Lesotho—digital migration ea e baka taba. Few people understand much about it, let alone why it they need it in the first place. The reasons the entire world is moving from analogue to digital is that analogue television is continuously varying. It is easily corrupted and consumes too much spectrum because it uses huge bandwidth.
“These disadvantages come along with unclear pictures, fewer channels and a need for use of aerials. Yet ariels are more easily disturbed by weather,” Mr Potsanyane said. With a digital system, a discrete code is used and the bandwidth is highly compressed. Meaning the already scarce spectrum is released.
“Suffice to say, it comes with lots of benefits such as clear pictures and a big number of channels. For instance, a minimum of four standard-definition digital channels can be squeezed on the spectrum currently occupied by one analogue channel,” he added.
The digital system, he explained, comes in three classes. The first class is terrestrial which depends on tower infrastructure, using the DVB T2 standard. Mainly used in Africa and Europe. The second class is satellite based and the third class depends on the use of cable system.
However, there are challenges to Lesotho’s digital migration system. Mr Potsanyane showed that most rural Basotho houses are built on slopes as they want to use the flat land for agricultural purposes. The highland is for wood sources and rangelands. Using data from the digital migration offices in Lesotho in combination with highly reliable software called radio mobile simulation software, he concluded that if a tower is placed on the mountain on whose slopes people dwell, they will not get any service. This is because they may be shut from the sight of such a tower (see the attached picture).
Besides, he explained that the terrestrial TV needs a line of sight from towers. In essence, the towers need to send and receive messages from one another. They need to see each other.
Yet, Lesotho’s slopes, valleys and hills, while beautiful, temper with the line of sight of towers. Hence some people may never enjoy the benefits of digital migration which almost everybody is looking forward to.
According to Mr Potsanyane, another factor compounding the problem is Lesotho’s level of development of the terrestrial infrastructure. With about twenty towers for the whole country. He has already found that many areas are simply not receiving coverage with the existing infrastructure.
The fewer the towers, the less effective they become. But if they are many, they become too expensive. Especially considering Lesotho’s sparse population settlements. It’s a catch-22 situation!
Mr Potsanyane did not only spot the problems with the digital terrestrial TV and stopped there. He also researched, analysed and evaluated other types of digital broadcasting. He found satellites to be reliable, efficient and especially appropriate for the Mountain Kingdom.
Unlike the terrestrial TV, the satellites being in space, always ensure line of sight communication with satellite receivers on the ground without obstacles. Once one has a satellite receiver, no matter how deep in the valley or high on the hill they may be. They will definitely access television services like anyone in the plain lowland.
“Satellite is 110% beneficial and appropriate for this country,” He emphasised.
After admitting he is no economist, Mr Potsanyane has a piece of advice or two for the government—an economic one! “It would be better if the government researches the efficacy of subsidizing the prices of purchasing satellite dishes for Basotho and improving the satellite system for digital broadcasting. I think this would be better than rushing to subsidize the set-top-boxes which would boost a terrestrial based system which is less likely to ensure blanket coverage,” He said.
Mr Potsanyane ended by revealing his motivations. He said that while most of his peers are enthused with building programs in their fifth year projects, he chose the evaluation route. He chose it because digital migration was a current and important national issue and he wanted to contribute to its development.
This blog post was originally written by NUL Research and Innovations