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What is the main different between GSM and CDMA service?

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GSM (Global System for Mobile communication) GSM is a digital mobile telephone system that is widely used around the world (especially in Europe). GSM uses a variation of TDMA and is the most widely used of all three digital wireless telephone technologies. GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot ---- CDMA (Code Division Multiple Access) CDMA, unlike TDMA and GSM, after digitizing data, spreads it out over the entire bandwidth available to it (unlike GSM and TDMA which place the calls side by side in three streams). Multiple calls are then overlapped on top of each other, and each is assigned a unique sequencing code to "unlock" the information only when and where it should be unlocked.
Posted: 26-03-2012 @ 12:36:18
In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including Sprint PCS, Cingular Wireless, Verizon and T-Mobile use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs. The GSM Association is an international organization founded in 1987, dedicated to providing, developing, and overseeing the worldwide wireless standard of GSM. CDMA, a proprietary standard designed by Qualcomm in the United States, has been the dominant network standard for North America and parts of Asia. However, GSM networks continue to make inroads in the United States, as CDMA networks make progress in other parts of the world. There are camps on both sides that firmly believe either GSM or CDMA architecture is superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful.
Posted: 24-03-2012 @ 11:29:26
GSM network signal is from towers CDMA network signal is from ground
Posted: 27-09-2011 @ 14:28:52
CDMA (Code-Division Multiple Access) refers to any of several protocols used in so-called second-generation (2G) and third-generation (3G) wireless communications. As the term implies, CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth. The technology is used in ultra-high-frequency (UHF) cellular telephone systems in the 800-MHz and 1.9-GHz bands GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1800 MHz frequency
Posted: 27-09-2011 @ 14:25:57
the difference between GSM and CDMA is as follows................... 1.DATA TRANSFER SPEED: With the advent of cellular phones doing double and triple duty as streaming video devices, podcast receivers and email devices, speed is important to those who use the phone for more than making calls. CDMA has been traditionally faster than GSM, though both technologies continue to rapidly leapfrog along this path. Both boast "3G" standards, or 3rd generation technologies. EVDO, also known as CDMA2000, is CDMA's answer to the need for speed with a downstream rate of about 2 megabits per second, though some reports suggest real world speeds are closer to 300-700 kilobits per second (kbps). This is comparable to basic DSL. As of fall 2005, EVDO is in the process of being deployed. It is not available everywhere and requires a phone that is CDMA2000 ready. GSM's answer is EDGE (Enhanced Data Rates for GSM Evolution), which boasts data rates of up to 384 kbps with real world speeds reported closer to 70-140 kbps. With added technologies still in the works that include UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access), speeds reportedly increase to about 275—380 kbps. This technology is also known as W-CDMA, but is incompatible with CDMA networks. An EDGE-ready phone is required. In the case of EVDO, theoretical high traffic can degrade speed and performance, while the EDGE network is more susceptible to interference. Both require being within close range of a cell to get the best speeds, while performance decreases with distance. Subscriber Identity Module (SIM) cards: In the United States only GSM phones use SIM cards. The removable SIM card allows phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself is tied to the network, rather than the actual phone. Phones that are card-enabled can be used with any GSM carrier. The CDMA equivalent, a R-UIM card, is only available in parts of Asia but remains on the horizon for the U.S. market. CDMA carriers in the U.S. require proprietary handsets that are linked to one carrier only and are not card-enabled. To upgrade a CDMA phone, the carrier must deactivate the old phone then activate the new one. The old phone becomes useless. 2.Roaming: For the most part, both networks have fairly concentrated coverage in major cities and along major highways. GSM carriers, however, have roaming contracts with other GSM carriers, allowing wider coverage of more rural areas, generally speaking, often without roaming charges to the customer. CDMA networks may not cover rural areas as well as GSM carriers, and though they may contract with GSM cells for roaming in more rural areas, the charge to the customer will generally be significantly higher. International Roaming: If you need to make calls to other countries, a GSM carrier can offer international roaming, as GSM networks dominate the world market. If you travel to other countries you can even use your GSM cell phone abroad, providing it is a quad-band phone (850/900/1800/1900 MHz). By purchasing a SIM card with minutes and a local number in the country you are visiting, you can make calls against the card to save yourself international roaming charges from your carrier back home. CDMA phones that are not card-enabled do not have this capability, however there are several countries that use CDMA networks. Check with your CDMA provider for your specific requirements. According CDG.org, CDMA networks support over 270 million subscribers worldwide, while GSM.org tallies up their score at over 1 billion. As CDMA phones become R-UIM enabled and roaming contracts between networks improve, integration of the standards might eventually make differences all but transparent to the consumer. The chief GSM carriers in the United States are Cingular Wireless, recently merged with AT&T Wireless, and T-Mobile USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin Mobile. There are also several smaller cellular companies on both networks.
Posted: 26-09-2011 @ 23:05:46
In CDMA a common band of frequencies is used, and different coding is used for different customers. In GSM different frequency bands are used each cellular geographical area, each customer is dynamically allocated to a frequency channel.
Posted: 26-09-2011 @ 14:55:52
CDMA (Code-Division Multiple Access) refers to any of several protocols used in so-called second-generation (2G) and third-generation (3G) wireless communications. As the term implies, CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth. The technology is used in ultra-high-frequency (UHF) cellular telephone systems in the 800-MHz and 1.9-GHz bands GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital wireless telephony technologies (TDMA, GSM, and CDMA). GSM digitizes and compresses data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900 MHz or 1800 MHz frequency
Posted: 10-09-2011 @ 09:46:35
if you are using a gsm mobile, you can change your phone's sim card when you want(example...in roaming)....but if you have a cdma mobile, then you cant and it can cost you, but, cdma is better for home network.....
Posted: 12-07-2011 @ 08:30:03
In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including Sprint PCS, Cingular Wireless, Verizon and T-Mobile use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs.
Posted: 29-06-2011 @ 09:53:13
gsm is stands for global system for mobile communication. it use tdma & fdma techniques as access mechanism . in gsm we devide bandwidth in to time slots for better utilization of bandwidth. cdma stands for code devision muliple access it use cdma techniques as access mechanism . in cdma we allocate a unique code for every user saparately and allocate bandwidth to user
Posted: 29-06-2011 @ 08:17:38
GSM stands for Global System for Mobile communication. It uses tdma & fdma techniques as access mechanism . In GSM we devide bandwidth in to time slots for better utilization of bandwidth. CDMA stands for Code Division Muliple Access. In cdma we allocate a unique code for every user saparately and allocate bandwidth to user based on that bandwidth code.
Posted: 28-06-2011 @ 22:32:21
GSM network signal is from towers CDMA network signal is from ground
Posted: 28-06-2011 @ 18:37:03
CDMA means code division multiple access ,while GSM means global system for mobile comunication..in india relaince provide cdma connection...
Posted: 28-06-2011 @ 18:27:10
1.GSM (Global System for Mobile Communications).............. GSM is the “branded” term referring to a particular use of TDMA (Time-Division Multiple Access) technology. GSM is the dominant technology used around the globe and is available in more than 100 countries. It is the standard for communication for most of Asia and Europe. GSM operates on four separate frequencies: You’ll find the 900MHz and 1,800MHz bands in Europe and Asia and the 850MHz and 1,900MHz (sometimes referred to as 1.9GHz) bands in North America and Latin America. GSM allows for eight simultaneous calls on the same radio frequency and uses “narrowband” TDMA, the technology that enables digital transmissions between a mobile phone and a base station. With TDMA the frequency band is divided into multiple channels which are then stacked together into a single stream, hence the term narrowband. This technology allows several callers to share the same channel at the same time. 2. CDMA (Code Division Multiple Access).............................. CDMA takes an entirely different approach from GSM/TDMA. CDMA spreads data out over the channel after the channel is digitized. Multiple calls can then be overlaid on top of one another across the entire channel, with each assigned its own “sequence code” to keep the signal distinct. CDMA offers more efficient use of an analog transmission because it allows greater frequency reuse, as well as increasing battery life, improving the rate of dropped calls, and offering far greater security than GSM/TDMA. For this reason CDMA has strong support from experts who favor widespread development of CDMA networks across the globe. Currently, you will find CDMA mostly in the United States, Canada, and North and South Korea. (As an interesting aside, CDMA was actually invented for the military during World War II for field communications.)
Posted: 28-06-2011 @ 17:10:23
GSM is a Global Syatem For Mobile Communication. GSM Operates 3 bands, 1) GSM 900 2) GSM 1800 and 3) GSM 1900. GSM 900 & GSM 1800 are used in india, But, GSM 1900 used in USA. GSM and CDMA techniques can be explained with an example, suppose there are 10 persons in a room and they want to communicate with each other .How can they communicate? First method:One persons speaks at one time that means we have provided a definite time interval to that person.-GSM Second method :all the peers speak at a time in a different language which we call as CDMA CDMA stands for Code Division Multiple Access and GSM stands for Global system for Mobile Communication. In CDMA phones the software is integral with the phone instrument and in the case of GSM phones it is through the SIM Card. CDMA phone instruments are dedicated to the service provider. GSM phone instruments are portable across service providers through SIM cards. The main difference between GSM and CDMA is: In GSM, the entire frequency band is not available to the end-user, while in CDMA the entire frequency band is available to the end-user. So, the Frequency Re-use factor is 1 in CDMA. GSM Works as follows: --------------------- The entire frequency band is divided into chunks and each such chunk is divided into timeslots and each such portion is made available to a user. CDMA Works as follows: ----------------------- The entire frequency band is available to the user. So, in order to differentiate, the transmission from each user is "spread" or coded using an unique code given to individual user. At the receiving end, the spread information is decoded.
Posted: 28-06-2011 @ 15:08:21
cdma cant be used in all mobiles but gsm can
Posted: 28-06-2011 @ 14:48:55