|
Welcome to the new home of the Celtnet Mobiles in formation site. This page is the sixth in a series of eight articles that takes you through how mobile phones work. You can either page through the aritcles, below, or you can use the navigation menu on the left to find the page you want.
In part 3 of this introduction to mobile phones and mobile phone technology the history of GSM technology and how it works was introduced.
GSM was a revolutionary standard that brought about the current mobile phone revolution and which also introduced interoperability between networks and country. Indeed, without GSM it would not be possible to buy a mobile telephone that works in most countries of the world. GSM networks are also allowing parts of the world, such as Africa where landline networks are often primitive and of low coverage to become integrated parts of the modern digital world. Indeed, without this revolution I would find if very difficult to communicate with my wife in Senegal, West Africa.
The Limitations of GSM
However, GSM is a technology of the mid 1980s where the only usage envisaged for a mobile phone is that of transmitting and receiving voice data. In fact, basic GSM phones only send and receive data at an apalling transmission rate of 9.6 kbps (kilobits per second). However, as mobile phones have grown into multimedia devices and text messaging has proved to be the 'killer app' — the one usage that brought mass appeal to mobile phones — then the data throughput limit has proved to be a real bottleneck. It's even possible to access the text content of web pages that have been converted to WAP (Wireless Access Point) format with a GSM phone. Unfortunately, due to the slow data transfer of GSM phones it can actually take several minutes to download even a WAP-converted page to your phone.
In Japan this limitation was overcome by the DoCoMo company with their extremely successful I-mode range of mobile phones which can transfer data at ten times the speed of standard GSM. Standard GSM uses circuit switching as a means of data transfer. This means that the phone must make a dedicated connection with the base station thus tying-up the channel completely for that phone. In contrast, I-mode uses technology borrowed from the Internet, called packet switching where the transferred data is broken up into blocks called 'packets'. Each packet is labelled with the address of the final destination and any packet can be transferred on any available channel and no channel is dedicated to any telephone. Because of this data transfer proceeds at a much, much, higher rate. Not only are downloads quicker, but as the phone is only connected to the network when a package of information is being sent users pay for the amount of data they have sent rather than for the total time they remain connected.
It is planned that all GSM networks will move to packet switching technology, which can only be of benefit to customers and it envisaged that data transfer rates will reach up to 171 kbps with the introduction of a system called GPRS (General Packet Radio Service) which not only splits the mobile phone call into packets but also allows each phone to use several channels which are shared amongst many users. Thus not only is data transfer speed increased but overall throughput is also increased.
Beyond GSM — 3G
3G, which stands for 'Third Generation' is the great white hope of many mobile operators. The International Telecommunication Union (ITU) has defined the demands for third generation mobile networks with the IMT-2000 standard. An organisation called 3GPP has continued that work by defining a mobile system that fulfils the IMT-2000 standard. This system is called Universal Mobile Telecommunications System (UMTS). The first stage in the evolution of GSM to UTMS is the introduction of GPRS to all GSM services.
Another advance in 3G systems is CDMA (Code Division Multiple Access) which allows a single 'burst' of data to carry several signals simultaneously. This further compresses the amount of data that can be sent in a single data burst and, theoretically at least, allows for a maximum data transfer rate of up to 2 Mbps (megabits per second).
It is this increased data transfer rates that allows 3G services to deliver video to its subscribers and which should also allow video messaging between 3G mobile phones. It is the hope of the nascent 3G providers that this video communication will be 'killer application' that drive through the sales of 3G phones and systems (just as texting did for GSM).
Not found what you're looking for? Search the web:
One Million People CampaignIf you can spare $1 then help support this site and change someone's life forever? Learn how and why on the One Million People campaign page. Or donate $10 and get my guide to spices ebook or The Recipes of Africa eBook as a gift for your donation! |
GPS Tuner Atlas Full version with North America Basic map content Atlas, is an outdoor navigational software for windows mobile devices, with built-in Tele Atlas maps, raster maps, and user generated custom calibrated maps.
If you are in search of company for your iPhone application development then visit Perception System
Bangalore: Verity Technologies, a mobile applications company with focus on Authentication and Identity Management Services, today announced a strategic alliance with Kores (India) Limited, a 76 year old highly diversified business house with all India network and market leadership in stationery and office products. Kores has relationships with most Indian Banks. The alliance paves way for Kores to distribute Verity’s highly acclaimed Blue ID, a new generation technology – that secures financial transactions, manage access and provides biometric identity to masses on a pan India basis.
Perception System has professional Iphone Games developers to built different levels of iPhone games as per your cost, budget and requirements within a certain period of time. Perception System http://perceptionsystem.com/iphone-game-development.html , offers great value at affordable cost to deliver our customers high quality game services.
Perception System know-how to proves quality and cost effective porting solutions. If you want our iPhone porting services please contact us at http://www.perceptionsystem.com Perception System offer both operator specific and handset specific porting services.
A handy app, SmartTouch Mobile enhances your Windows Mobile device functionality with a suite of widgets, enabling smooth access to branded content and services.
iPhone 3G is the coolest mobile phone launched lately, even though it is cheaper than its earlier version but there are a lofty subscription charges involved. You can spare yourself from these costs and gift yourself a free iPhone 3G.
iPhone is a revolutionary cell phone and has changed the cell phone industry completely. But it is cell phone which is out of reach of many. There are a lot of websites which are offering free iPhones.
Are you one of the thousands of people with an old mobile phone languishing in the corner? If you are then why not contact Envirofone.com they could give you up to £150 for your old phone. It’s better than having that old phone sitting around doing nothing. Read the full story to find out more…
While there still aren’t any physical copies of cell phone directories in our times yet, it is already possible to know the names and addresses of any cell phone number if you will use a cell phone lookup website. If you still aren’t aware with this, then read on this article and we will explain it to you more and more.
A cell phone lookup resource is an online tool that any person can use to search and retrieve any essential information about a cell phone number owner. For example, through a cell phone lookup tool, you can know the full legal name of the person behind the number.
click here for the full story
printer version