Short Tutorial of Cellular Networks
Tutorial April 8th. 2006, 9:26amThis short tutorial is intended for you who have no ideas when reading terms like EDGE and W-CDMA. My idea of writing this blog is because there are so many acronyms in the cellular technology. Sometimes we just got confused. I have heard some people confuse cdmaOne with W-CDMA. They think both are the same thing, which is actually not the case.
How do I start? It’s a bit tricky to start the tutorial because so many things are going on. Basically, there are two cellular technology that are mostly used today, i.e. GSM and cdmaOne. Some people call it cdmaOne as CDMA only, for example, you may hear someone saying “this is a CDMA phone”. cdmaOne, which is developed by Qualcomm, is popular in North America and some other countries. GSM, which is originally from Europe, is more popular in the rest of the world. Both GSM and cdmaOne are the second generation (2G) of cellular networks. The difference between 1G and 2G is the fact that 2G is based on digital technology, while 1G is still based on analog technology.
Now, let’s go the more interesting part. As you know that 2G network is not fast enough. We need faster network. That’s why 3G has been deployed in some parts of the world. How do we go to 3G then? Since we have two technologies, i.e. GSM and CDMA, there are two upgrade paths to go there.
GSM
- 2G: GSM
- 2.5G: GPRS
- 2.75G: EDGE / EGPRS
- 3G: W-CDMA
- 3.5G: HSDPA & HSUPA
The upgrade path for GSM operators to 3G network is W-CDMA. As you can see from the list above, there are some additional steps before we finally have 3G network. We have GPRS as 2.5G network and EDGE (or EGPRS) as 2.75G network. The reason why we have additional steps was because 3G investment is not small amount of money; while customers already need more speed.
The most common W-CDMA technology used in the world is UMTS. Sometimes UMTS is also called 3GSM, so that people notice that it is based 3G network based on GSM. Is there another W-CDMA technology beside UMTS? The answer is yes. NTT DoCoMo from Japan has developed another 3G network, called FOMA. It is actually the first 3G network deployed in the world back in 2001.
Even though 3G network is not really deployed world wide yet, people are already talking about the next generation of cellular networks. That’s why these days we hear HSDPA, which is referred as 3.5G network and HSUPA, which is sometimes referred as 3.75G network.
CDMA
- 2G: cdmaOne
- 2.5G: CDMA2000 1xRTT
- 3G: CDMA2000 1xEV-DO & CDMA2000 1xEV-DV
Now, the second path to go to 3G is based on cdmaOne technology. As you can see from the list above, the real 3G network for CDMA is actually CDMA2000 1xEV. Like GSM, there is an upgrade step before going there, i.e. CDMA2000 1xRTT.
For the 3G network itself, there are two types of networks, i.e. 1xEV-DO which is optimized for data only; and then 1xEV-DV, which is optimized for data/voice.
Acronyms
Now, here is the list of all acronyms above:
- CDMA: Code Division Multiple Access
- CDMA2000 1xRTT: CDMA2000 1 times Radio Transmission Technology
- CDMA2000 1xEV-DO: CDMA2000 1x Evolution Data Optimized
- CDMA2000 1xEV-DV: CDMA2000 1x Evolution Data Voice
- EDGE: Enhanced Data rates for GSM Evolution
- EGPRS: Enhanced GPRS
- FOMA: Freedom of Mobile Multimedia Access
- GPRS: General Packet Radio Service
- GSM: Global System for Mobile Communications
- HSDPA: High Speed Downlink Packet Access
- HSUPA: High Speed Uplink Packet Access
- UMTS: Universal Mobile Telecommunication System
2 Responses to “Short Tutorial of Cellular Networks”
Comments are disabled.
July 31st, 2006 at 11:10 am
I read your tutorial while learning about telephony. I have been involved in soft switches used as tandems for since 1998 and I have been pulled into the Distributed MSC products for Alcatel.
Some of the language confuses me. It appears that GSM defines the entire system: BSS and MSC while CDMA defines an access technology only and the MSC is generic. Is that correct?
Regards,
DS
July 31st, 2006 at 11:52 am
@Dale: That is a very good question. I am not really sure about that, but as far as I know MSC is GSM specific. Read more information about it at http://en.wikipedia.org/wiki/Mobile_Switching_Center.