A Primer on LTE

LTE or Long Term Evolution is a 4G wireless technology and is considered the next in line in the GSM evolution path after UMTS/HSPDA 3G technologies. LTE is espoused and standardized via the 3GPP or 3rd Generation Partnership Project members. 3GPP is a global telecommunications consortium having members in most GSM dominant countries. 3GPP specifications are based on GSM evolution path of wireless communications. GSM is the most prevalent wireless standard in the world and has maximum number of subscribers globally.

The impact of LTE is so big that even powerful carriers which were on the alternate CDMA path like Verizon Wireless of United States, have decided to go with LTE in their next generation 4G evolution. Firms like Verizon and MetroPCS of USA have all but dumped the CDMA technology path almost dealing a blow to the CDMA owner Qualcomm, although the latter is much more diversified so it is not really short of business models.

LTE vs WiMAX
Whereas WiMAX emerged from the WiFi IP paradigm, LTE is a result of the classic GSM technology path. LTE is behind in the race to 4G with WiMAX getting an early lead with the likes of Sprint ClearWire and several operators in Asia opting to go with WiMAX in the near term. So where WiMAX has a speed to market advantage, LTE has massive adoption and GSM parenthood to back it up.

It is widely believed by market analysts that LTE will win ultimately but WiMAX will find adoption in frontrunner communities and niche business models which tend to take up technology faster. WiMAX vendors will have you believe that speed to market is too important to ignore. History suggests otherwise in case of wireless industry. It is also believed that ultimately, wireless industry will figure out a way to wed the two 4G technologies so the end product in few years might be a nice amalgam.

So ultimately, what standard an operator uses might be a moot point in the long run. The inter-operability would be just too great to get hung up on the wireless standard. The fact that both WiMAX and LTE are all-IP means that a cross-connection will be a piece of cake at some point in future.

In terms of speed, Fixed WiMAX lacks LTE in speed but Mobile WiMAX may catch up with LTE on this front. For an overview on WiMAX, refer to our post “A Primer on WiMAX“.

LTE Technology
LTE builds on 3GPP family which includes GSM, GPRS, EDGE, WCDMA, HSPA (High Speed Packet Access) etc. LTE is an all-IP standard like its peer WiMAX. LTE allows for rich applications and business models which include ultra-high speed voice, video and data. It also enables integration with the classic internet infrastructure which is all-IP based.

HSPA (High Speed Packet Access), the 3G GSM standard popular over near-term, offers uplink speeds of 11.5 MBPS and downlink of 28 MBPS. Whereas LTE offers 75-100 MBPS Uplink speeds and 250-300 MBPS downlink speeds. Compare this with 20 MBPS U-verse speeds of AT&T wired broadband network U-verse and 50 MBPS speeds in Verizon FIOS TV service. In a nutshell, LTE will beat the fastest wired broadband delivery High Def TV today (in USA) by order of 1 to 4 or 1 to 2 depending on which wired broadband we are talking about. That said, many carriers like AT&T believe that HSPA and its faster cousin HSPA+ will compare well with early WiMAX speeds and so there is no rush to LTE yet for these kind of carriers.

Some key characteristics of LTE are described below :

• Increased Data Rates and High Efficiency : LTE is based on OFDM Radio Access technology and MIMO antenna technology (just like its cousin WiMAX) which offer excellent modulation technique for achieving powerful spectral efficiency.  Think of the OFDM wireless spectrum as a series of very fine and narrow wireless  bands and each band gets allocated to various service providers.  LTE offers higher data transmission rates while utilizing the spectrum more efficiently. This translates to an ability to support many more multitude of subscribers than is possible with pre-4G spectral frequencies. LTE is 2 to 5 times more efficient in spectrum utilization than the most advanced 3G networks.
• Radio Planning : LTE signal goes far and wide and covers a larger geographic territory. LTE signal is way faster than the existing wireless transmission resulting in higher user response times.
• IP environment : LTE is all-IP which permits new enhanced applications like real time voice, video, gaming, social networking and location-based services.  The concept of wireless ubiquity comes alive with LTE processor chips in everything from netbooks to mobile phones to consumer devices; all these devices talk to each other seamlessly and effortlessly.
• Inter-operability : LTE IP network co-operates with circuit-switched legacy networks resulting in a seamless network environment and signals are exchanged between traditional networks, the new 4G network and the IP-based internet seamlessly.

LTE Applications
LTE will enable applications previously unheard of. Wireless ubiquity is a given. All consumer devices. communication and computing resources may be enabled on the wireless network courtesy of chipmakers like Intel who are eagerly building in WiMAX and LTE in future chipsets which will be embedded in all sorts of technology devices that one can imagine.  Social Networking and human-technology interaction (HTI) will take on a new meaning. Human-technology interface and resultant communication could be as seamless and as effortless as the Tom Cruise movie Minority Report makes it out to be (ok we are bragging a bit now).

Web 4.0, if you will, may just comprise the Wireless as an integral element of the hyper-connected world via LTE and WiMAX enablement.  Broadband TV might not need wired cables anymore and new MVNO service providers may emerge who enable wirelessly driven TV and broadband internet. Business users might exchange massive amounts of data while on the go at the flick of a button (or touch). Interacting with your Flickr and Picasas photo streams from mobile devices might be a breeze. Games will cross wired / wireless domains and mobile location will figure in the gaming context naturally. Location-based may take a new meaning with location being the true IP beacon determining the application context in a flash, thereby offering a ultra-personalized mobile experience to the user.

LTE Timeline
Operators are just now fully deploying 3G using WCDMA or UMTS/HSPDA. WiMAX is coming in via ClearWire in USA and several operators like BSNL in India and many others in Middle East and Africa. The first LTE deployment in USA is with relatively tiny MetroPCS which may just beat the big 3 LTE carriers (AT&T, Verizon and T-Mobile) in the race to 4G. Verizon is claiming 2010 LTE deployment and AT&T is taking a more patient approach and states that LTE is in 2011-12 timeframe. China is unique, as usual. They have taken the TD-SCDMA 3G route which is a “unique to China” standard.  Chinese 4G strategy is not clear still. India is more LTE centric like the West with major carriers like Airtel and Vodafone adopting the LTE route. LTE in India is many years away as India’s regulator TRAI has not even awarded the 3G spectrum licenses yet.

Japan, we won’t even go there..