Everyone is mobile these days but you can still experience situations when you have no mobile coverage in certain parts of the world. And, no, not because there is no mobile network but because there are still two main standards for mobile networks - CDMA and GSM, which are largely incompatible. Not many people know the differences between CDMA vs GSM. In this article, we'll discover their key differences as well as advantages and disadvantages.\u00a0\r\nCode Division Multiple Access (CDMA) and Global System for Mobile Communication (GSM) are two variations of one and the same technology but still divide the world into two parts \u2013 countries that have adopted the CDMA technology and countries where the GSM networks prevail.\r\nActually, the debate about the advantages and disadvantages of CDMA vs. GSM is about to end with the gradual introduction of 5G networks, a technology that is designed, among other things, to finally merge the two standards. We nonetheless give you a detailed overview of the origins of CDMA and GSM, the differences between the two mobile network standards and how CDMA vs. GSM compare.\r\n\r\n\r\n\r\n\r\n \r\nWhat Is CDMA?\r\nThe Code Division Multiple Access is a technology widely used in the United States, Russia and some parts of Asia. The CDMA technology does not use a SIM card to identify a user on the network. The phone device is added to a whitelist by the carrier company and then uses their bands to make a connection.\r\nInitially, consumers were not allowed to use a CDMA phone, manufactured for one telephone carrier, into the network of another mobile network operator. With the emergence of the LTE networks, users get access to SIM-enabled CDMA phones, which in turn allows for switching between CDMA phone companies. Simply put, you can use a CDMA phone with different CDMA providers but mostly on LTE networks.\r\n\r\n\r\n\r\n\r\n \r\nAs far as the underlying CDMA technology is concerned, it allows users to access the entire spectrum of bands available, which increases the network\u2019s capability to handle more connections at a time. The technology is using a pseudo-randomized digital sequence to encode your conversation, thus protecting the content of your call by making voice data available only to the devices that take part in the conversation.\r\n \r\nWhat Is GSM?\r\nIf you look at the differences between GSM vs. CDMA from a consumer point of view, you will find that the major difference is that the GSM networks use SIM cards to store your data and enable users to make calls.\r\nThe SIM card holds data about the services available to the network subscribers in the same way a whitelist of CDMA phone numbers is working. You can easily change the GSM networks by simply getting a card by another GSM service provider and although some carriers do sell locked GSM phones you can switch providers more easily compared to CDMA networks, especially when travelling abroad.\r\n\r\n\r\n\r\n\r\n \r\nGSM networks rely on Time Division Multiple Access technology to transmit your voice conversations. TDMA assigns time slots to multiple conversation streams, then alternates them in sequence and switches between one conversation and another in short intervals. Data is being transmitted during these intervals and the network knows who are online by checking the available and connected SIM cards.\r\n \r\nCDMA Vs GSM -- Key Differences\r\nThe two image above show a two basic phone models by Samsung and Nokia, respectively. Both are able to do broadly the same things and have similar functionality but they cannot be used interchangeably until you have a dual CDMA and GSM functionality embedded into them.\r\n\r\n\r\n\r\n\r\n \r\nThat is because the CDMA and the GSM mobile networks share the same technological origins but use different methods for making calls and enable devices to transmit data. The basic technology is all the same but for example you cannot simultaneously transmit or receive data and voice over CDMA. There is way to do that but it requires an additional Wi-Fi connection.\r\nBelow, we have compiled a list of major features that make CDMA vs. GSM so similar and different in the same time.\r\n \r\nTechnology\r\nCDMA uses the entire spectrum of bands and code division technology (CDMA) while the GSM operates through both Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA) for user and cell separation.\r\nGSM connections are SIM-specific while CDMA connections are device-specific.\r\n \r\nBand Spectrum Frequencies\r\nThe CDMA network uses the frequency spectrum of CDMA 850 to CDMA 1900 to operate. The GSM network is using the frequency spectrum between GSM 850 MHz and GSM 1900 MHz to operate.\r\nA network tower in each GSM cell serves a phone located in its area of coverage while the CDMA establishes a physical channel and a dedicated code for each device in the network.\r\nAlso, CDMA covers larger areas with fewer towers, which makes the technology popular in countries with vast rural areas.\r\n \r\nTransfer Of Data\r\nCDMA offers faster data transfer rate as compared to GSM. It uses the EVDO data transfer technology that offers maximum download speeds of 2 mbps while the EDGE technology the GSM uses offers maximum download speeds of 384 kbps.\r\n \r\nVoice And Data Transmission\r\nWhen you compare CDMA vs. GSM, you need to be aware that the GSM technology enables transmission of voice and data in the same time while the CDMA technology cannot do that.\r\n \r\nGlobal Coverage\r\nGSM networks are available in more than 200 countries worldwide, which makes the GSM a more popular technology as compared to CDMA.\r\nAs we said, CDMA is in the wide use mostly in North America, Russia and Asia but you should be aware that countries like the United States and Russia operate both CDMA and GSM networks. GSM networks operate alongside CDMA carriers in virtually any country where CDMA is the prevailing technology.\r\nNonetheless, roaming for CDMA phones might be a problem in some locations while using a GSM phone abroad is rarely a problem as carriers as a rule have contracts for coverage anywhere in the world.\r\n \r\nCall And Data Security\r\nComparing CDMA vs GSM is also about security as mobile phone calls and mobile data transfer is now part of our everyday personal and business lives.\r\nThe CDMA offers higher level of security in comparison to GSM networks and the CDMA signal is hard to even detect without professional equipment involved in targeted attack. Overall, calls on CDMA networks are considered more secure unless someone specifically sniffs on you.\r\n \r\nPhone Radiation\r\nGSM phones expose their users to higher radiation levels. They emit close to 30 times more radiation as compared to CDMA devices. That is so because GSM emits continuous wave pulses while CDMA phones do not need to emit wave pulses to operate.\r\n \r\nAdvantages And Disadvantages Of CDMA Vs GSM\r\nYou can easily spot some advantages of GSM over CDMA and vice versa. After looking at the list above, but there are also certain business and engineering advantages and disadvantages associated with each technology.\r\nLet\u2019s take a look at those business benefits and downsides of both CDMA and GSM.\r\n \r\nAdvantages Of Using CDMA\r\n\r\n \tFull utilization of fixed frequency spectrum\r\n \tFlexible resource allocation\r\n \tLarge signal bandwidth reduces multipath fading\r\n \tUnlimited number of users\r\n \tIndecipherable code\r\n \tChanging cells does not affect signal\r\n \tThe CDMA channel is nominally 1.23MHz wide.\r\n\r\n \r\nDisadvantages Of Using CDMA\r\n\r\n \tHigher sophistication\r\n \tServices quality decreases with increasing number of users\r\n \tLimited upgrade options\r\n \tLack of international roaming\r\n\r\n \r\nAdvantages Of Using GSM\r\n\r\n \tBetter\u00a0 spectrum efficiency\r\n \tLower cost of equipment\r\n \tHigh-quality voice calls\r\n \tInternational roaming\r\n \tCompatible with Integrated Services Digital Network (ISDN)\r\n\r\n \r\nDisadvantages Of Using GSM\r\n\r\n \tLimited number of users per cell tower\r\n \tQuestionable security\r\n \tSlower data transfer\r\n\r\n \r\nAs you can see, comparing CDMA vs. GSM networks uncovers multiple advantages and disadvantages of these technologies and this list is barely complete.\r\nIn any case, the differences are hardly noticeable to the average user. Unless you leave for a location where a CDMA or GSM phone does not work because of incompatibility with the local mobile network.\r\n \r\nFinal Thoughts\r\nYou can compare CDMA vs. GSM on many levels. But, you will find one of the technologies offers certain advantages over the other.\r\nThe truth is that GSM technology has conquered the world with over 80 percent of global users relying on GSM. This is in comparison to 24 percent who use CDMA.\r\nThe fifth generation of mobile networks will put an end to the CDMA vs. GSM divide and will create a mobile ecosystem where both the standards will work seamlessly and in synchrony.