By LEONG HUNG YEE
hungyee@thestar.com.my
DO you know that remote-controlled cars – yes, the children’s (and adults with such fetishes) plaything with forward, backward and left and right turn functions – use spectrum? These toys are designed with radio-controlled systems to enable users to control via radio waves so that it will perform multiple functions.
On top of that, there are other things in our daily routine that uses spectrum such as the auto gate at your home, television, wireless Internet connectivity, radio and mobile phones.
But what really is this thing called spectrum?
“Basically, spectrum refers to a range of radio frequencies. The bandwidth of a radio signal is the difference between the upper and lower frequencies of the signal,” explains an industry player.
In simpler terms, spectrum refers to the range of frequencies over which electromagnetic radio frequencies signals can be sent. It includes radio, television, wireless Internet connectivity, remote control toy race cars, and every other communication enabled by radio waves.
He enlikens spectrum to a dedicated parking space for a respective unit in a condominium. “The parking lot is yours. No one else can park it there or they risk their cars being clamped unless you rent it out to your neighbour who has a few cars.
“A spectrum belongs to a specific operator. Only that particular telco can operate in that space to avoid interference with others. Of course, if they have excess capacity, they can rent it out to other operators,” he says.
Other industries such as defence, the police force, fire brigade, ambulance and maritime enforcement agency also use spectrum for radio communications.
A voice signal has a frequency of 200 hertz (Hz) and a maximun frequency of 3,000 Hz while the bandwidth is 2,800 Hz about 3KHz.
“The amount of bandwidth needed for 3G services could be as much as 15 to 20 Mhz, whereas for 2G services, a bandwidth of 30 to 200 Khz is used. Hence for 3G, huge bandwidth is required to enable services such as video calling and internet access,” he adds.
According to Malaysian Communications and Multimedia Commission (MCMC), spectrum means the continuous range of electromagnetic wave frequencies up to and including a frequency of 420 terahertz.
Generally, no one shall intentionally transmit in any part of the spectrum to provide a network service unless the person holds a spectrum assignment, an apparatus assignment or a class assignment.
All three assignments are stipulated in the Malaysian Communications and Multimedia Act 1998, Spectrum Regulation 2000 and other guidelines issued by the MCMC.
However, MCMC may issue a spectrum assignment which confers rights on a person to use one or more specified frequency bands. Telecommunications companies will need to buy a frequency spectrum from the rightful governing bodies, which in this country is MCMC, to set up a data or voice network.
“Telcos can only transmit data at the frequencies for which they are licensed to avoid interference with others. Because there are multiple users on the network using the frequency at one time, there are different methods that telcos use to make sure information can be transmitted and received seamlessly by customers,” says the industry player.
In different parts of the world, different organizations allot parts of the overall electromagnetic spectrum to different uses.
Locally, the MCMC governs the allocation of spectrum. In Singapore, it is the Singapore Infocomm Development Authority while in the United States, it is the Federal Communications Commission. Globally, the spectrum is governed by the International Telecommunication Union (ITU).
In many parts of the world, international agreements are also required so that communications systems in neighbouring countries will not interfere with each other.
There is no common band plan as all countries have a different band. And the spectrum is allotted for various purposes such as television. For example, the FM radio station gets certain slots while AM radio stations have different slots and similarly for cellular communications which have their own slots.
As the world becomes increasingly wireless (with cordless phones, cell phones, wireless Internet and GPS devices), allocation of the available spectrum to each technology is expected to become increasingly contentious.
“Bandwidth is something that we just can’t get enough of, or to put it another way, there’s no such thing as too much bandwidth.
“Just when you think that you’ve got enough bandwidth to do your stuff, out comes another technological advancement that says the opposite. If you ask frequent Internet users, the first thing that they would say is that they need more bandwidth,” an analyst says.
The first generation networks used are analog while the second generation (2G) networks are digital and 3G technology is used to enhance mobile phone standards. The highlight of 3G is video telephony which enables users to use video call function.
Although the country had just embraced the third-generation (3G) in 2005, we are now moving towards the 4G directions.
In May 2005, Celcom became the first local telco to launch 3G services in Malaysia and Maxis launched its 3G phone service in July the same year.
The first 3G bid happened in 2002 where MCMC awarded two blocks of spectrum to Telekom Malaysia Bhd and Maxis Communications Bhd then. Subsequently, the regulator opened a second round of 3G bid and awarded it to Time dotCom Bhd and MiTV Corp Sdn Bhd.
Recently, MCMC has allocated the 2.6GHz spectrum a block of 20MHz to nine cellular/wireless companies that is meant for long-term evolution (LTE) or 4G.
The regulator is allocating 20Mhz bandwidth, TDD or FDD, for each player but the location of the block will be decided later. The LTE will enable users to transfer large files to and enjoy streaming video on mobile devices, as well as watch almost high-definition quality video.
Celcom Axiata Bhd and Maxis Bhd had announced they had undertaken trials for 4G.
http://biz.thestar.com.my/news/story.asp?file=/2010/10/23/business/7265905&sec=business
No comments:
Post a Comment