Tuesday, 27 March Uplink and Downlink of LTE LTE works on two different types of air interfaces radio linksone is downlink from tower to deviceand one is uplink from device to tower. By using different types of interfaces for the downlink and uplink, LTE utilizes the optimal way to do wireless connections in both of the ways which makes a better optimized network and better battery life on LTE devices. Having MIMO means that devices have multiple connections to a single cell, which increases the stability of the connection and reduces latency tremendously and it also increases the total throughput of a connection. MIMO is what lets
You have probably come across these terms in the past, when picking a mobile phone, or when first joining, or switching, network carriers, but what do they mean, and what is the difference between the two?
GSM stands for Global System for Mobile Communication, and is now considered the standard for communication globally, particularly in Asia and Europe, with its availability in over countries worldwide.
The GSM Association is an international organization founded inthat is intended to develop and oversee the expansion of the GSM wireless standard. With GSM, our voice is transformed into digital data, which is given a channel and a time slot.
On the other end, the receiver listens only to the assigned time slot, with the call pieced together.
You can find the full list of CDMA networks here. CDMA networks layer digitalized calls over one another, assigning unique codes to differentiate between them. Every call data is encoded with a different key, and the calls are then transmitted at the same time.
The receivers each have the unique key as well, to split the combined signal into its individual calls. Differences Shutterstock Both are multiple access standards, which means that multiple calls can go through a single tower, but as you can see, the major difference between the two has to do with the way your data is converted into the radio waves that your phone broadcasts and receives.
There are of course, more practical considerations that matter more for us as a consumer, which you can find listed below — SIM cards: In other words, CDMA is a handset based standard, with a phone number linked to a particular device. If you wanted to upgrade to another phone, you would have to get in touch with the network carrier, de-activate the old device and activate the new one.
On the other hand, with GSM devices, the phone number is linked to the SIM card, so when switching devices, all you have to do is pop the SIM card into a new phone and you are good to go. This is obviously without taking into consideration GSM devices being locked to network carriers, as seen in the US.
However, when it comes to international roaming, GSM has the upper hand, with their being a lot more GSM networks around the world, along with roaming deals between these providers.
With a GSM phone, you also have the advantage of picking up a local SIM card wherever you are, assuming that you have an unlocked device.
You may not get full access to data connectivity, depending on the device and network compatibility though. Unless international roaming is a factor, as far as your voice call and 3G data needs are concerned, both GSM and CDMA networks are equally good, with factors like availability, coverage, customer service, and price, more at play here.TDMA vs CDMA Ever since the invention and commercialization of cellular systems, industry leaders and engineers had already foreseen the inevitable overcrowding of simultaneous callers because the number of accessible channels is very limited.
RF engineers of the industry are now using methods to remedy these problems. Chapter 2 Cellular Systems Wireless communications are especially useful for mobile applications, so wireless systems are often designed to cover large areas by splitting them into many smaller cells.
The CDMA is based on spread spectrum technology which makes the optimal use of available bandwidth. It allows each user to transmit over the entire frequency spectrum all the time.
Learning Services - Testing Remote Lab Connectivity PDF.
Documents Product Documents. Product. GSM vs CDMA – What’s the difference. The Best. GSM uses a variant of TDMA (time division multiple access) that divides the frequency bands into multiple channels. CDMA, or code. Key Differences between FDMA vs. TDMA Technology December 2, by Icom America FDMA (Frequency Division Multiple Access) and TDMA (Time Division Multiple Access) technologies are used in P25 and in business and industrial digital radios (P25 Phase I & NXDN™ for FDMA; P25 Phase II & DMR for TDMA).