4G Technologies

The 4G is the fourth generation of cellular wireless standards. It is used broadly to include several type of broadband wireless access communication not only cellular telephone system.4G is an IP-based heterogeneous network. One of the terms used to describe 4G is “MAGIC”,

M-Mobile Multimedia A-Anytime anywhere G-Global mobility Support I-Integrated wireless solution and C-Customized personal service

While most of us are used to getting high speed Internet connections at home, the office or even the local cafe, once we are on the road those high speeds have to stay behind. With 4G the promise is that you can get real mobile broadband to go. In this piece I am going to tell you all about the technology and its benefits.

But first, some background: 4G is the short name for fourth-generation wireless, the stage of mobile communications that will enable things like IP-based voice, data, gaming services and high quality streamed multimedia on portable devices with cable modem-like transmission speeds. It's a successor to 2G and 3G wireless, whereby the first signified the shift from analog to digital transmissions, bringing data services like SMS and email to mobile phones for the first time, and the second refers to the advent of things like global roaming as well as higher data rates.

Think of wireless generations as a handful of services that get faster and more feature-rich as newer technology becomes available. The 3G networks that we use today allow us to stream video, download music and files, and surf the web at average download speeds from 600Kb/s to 1.4Mb/s. With 4G you'll be able to do the same but at much faster rates, while the extra bandwidth opens the door for newer applications.

Wireless Network Growth and Evolution

Comparison with Generations

Although no set of standards have been established as of yet by the International Telecommunication Union (ITU), two competing technologies have been proposed: LTE and WiMAX. Many service providers often use the term 4G mobile broadband to describe the technologies they are offering based on their own, sometimes distorted definitions. However, current implementations are largely considered pre-4G, as they don't fully comply with the planned requirements of 1Gbit/s for stationary reception and 100Mbit/s for mobile.

Besides speed, there are other guidelines that must be met for wireless communication standards to qualify as 4G. In a nutshell, they should be very spectrally efficient, should dynamically share and utilize the network resources to support more simultaneous users per cell, have smooth handovers across heterogeneous networks, offer high quality of service for next generation multimedia support, and should be based on an all-IP packet switched network.

LTE

Short for Long-Term Evolution, LTE is considered by many to be the natural successor to current-generation 3G technologies, in part because it updates UMTS networks to provide significantly faster data rates for both uploading and downloading. The specification calls for downlink peak rates of at least 100Mb/s and an uplink of 50Mb/s, but going by real world tests its transfer speeds will more likely range from 5-12Mb/s for downloads and 2-5Mb/s for uploads.

LTE is being developed by  the 3rd Generation Partnership Project, or 3GPP, as an eight release of what has been evolving since 1992 from the GSM family of standards.

Long Term Evolution (LTE) is a radio platform technology that will allow operators to achieve even higher peak throughputs than HSPA+ in higher spectrum bandwidth.

The overall objective for LTE is to provide an extremely high performance radio-access technology that offers full vehicular speed mobility and that can readily coexist with HSPA and earlier networks. Because of scalable bandwidth, operators will be able to easily migrate their networks and users from HSPA to LTE over time.

LTE assumes a full Internet Protocol (IP) network architecture and is designed to support voice in the packet domain.

There are two fundamental aspects of LTE. The first is that the technology finally leaves behind the circuit switched network of its GSM roots and moves to an all-IP flat networking architecture. This is a significant shift which in very simple terms means that LTE will treat everything it transmits, even voice, as data. The other big change relates to the use of MIMO technology, or multiple antennas at both the transmitter and receiver end to improve communication performance. This setup can either be used to increase the throughput data rates or to reduce interference.

The Growth Path

Many big-name global operators and mobile communications companies are backing LTE in the race for 4G mobile broadband, including Vodafone, Orange, T-Mobile, LG Electronics, Ericsson, Nokia, Siemens, NTT DoMoCo, and others. In the U.S., Verizon Wireless has said it is going commercial with its LTE network in the fourth quarter, with 25 to 30 markets up and ready at launch. AT&T and T-Mobile claim they will begin to deploy LTE in 2011, but in the meantime both networks have moved to HSPA 7.2 and the latter plans to roll out HSPA+ beginning this year. Theoretically these can support speeds of up to 7.2 and 21 Mbps, respectively, but in real world scenarios they are only marginally faster than most 3G data services.

The reason behind LTE’s strong industry support lies in the relative ease of upgrading from current 3G networks worldwide over to LTE mobile broadband, compared to the significant infrastructure build out that WiMAX has taken thus far. Fewer cell sites have to be built and penetration into buildings is better at the 700 MHz spectrum LTE uses. However, WiMAX deployments are already up and running while LTE's formal debut is still a few months out.

WiMAX

The wireless bandwidth will be roughly 3Mbps/1.5Mbps; but this is nowhere near the +100Mbps/50Mbps that LTE promises

 It has helped to provide the portable internet connection throughout the cities for various devices. It provides DSL cable option to provide to service to miles. It provide telecommunication, IPTV service

WiMAX is a wireless broadband access standard developed and maintained by the IEEE under the 802.16 specification. As its name suggest, WiMAX can be thought of as an extension of Wi-Fi designed to enable pervasive, high-speed mobile Internet access on a wide range of devices, from laptops to smartphones. The current implementation is based on the 802.16e specification which offers theoretical downlink rates upwards of 70Mbps and up to 30-mile ranges.

Again, "theoretical" is the keyword here as WiMAX, like all wireless technologies, can either operate at higher bitrates or over longer distances but not both. Production networks being operated in the United States are seeing average speeds go from 3 to 6Mb/s, with bursts up to 10Mb/s. Like LTE -- and Wi-Fi 802.11n for that matter -- WiMAX supports MIMO technology, which means that additional antennas can increase the potential throughput.

There is no uniform global licensed spectrum for WiMAX, but three have been listed: 2.3 GHz, 2.5 GHz and 3.5 GHz. In the U.S., the biggest segment available is around 2.5 GHz and is already assigned primarily to Clearwire, a wireless internet service provider in which Sprint Nextel holds a majority stake.

In terms of total available 4G spectrum to deploy their services, Clearwire has several times more than its competitors, which have smaller portions of the 700 MHz band. However, Verizon and AT&T are not too worried about this as they can re-utilize spectrum being used right now for 2G and 3G services by upgrading these to LTE when the demand is there.

Furthermore, as mentioned earlier, the 700 MHz band that both Verizon and AT&T plan to use has enormously better range and penetration of buildings than the same power of signal at 2.5 GHz. Some experts have said that 700MHz will require as few as one-quarter as many base stations to offer identical coverage to 2.5 GHz.

As you might have guessed, the industry players behind these 4G technologies reflect the history of each standard. Whereas LTE biggest supporters are, in general, telecommunication service companies and handset manufacturers, WiMAX counts the likes of Intel, Cisco and Google among its most important backers. It should be noted though that many companies like Nokia or Motorola are members of both industry groups, with different levels of involvement.

The 'Real' 4G, Products and Availability

The 'Real' 4G Still a Long Ways Off?

Like I mentioned before, neither WiMAX nor LTE are truly considered a 4G technology by the International Telecommunications Union. As defined in their International Mobile Telecommunications Advanced (IMT Advanced) family of standards, these technologies must have target peak data rates of approximately 100 Mb/s on high mobility devices like cell phones and approximately 1 Gb/s for stationary devices like a 4G modem at home.

Just like the so-called 2.75G EDGE standard was developed to provide speeds several times faster than 2G data (GPRS) before 3G could be deployed, current implementations of WiMAX and LTE are largely considered a stopgap solution that will offer a considerable boost while WiMAX 2 (based on the 802.16m spec) and LTE Advanced are finalized. Both technologies aim to reach the objectives traced by the ITU, but are still far from being implemented.

In the United States, both T-Mobile and AT&T have moved to UMTS and various flavors of paired HSDPA / HSUPA, while on the CDMA front Sprint Nextel and Verizon Wireless support the EV-DO network. Download speeds vary from carrier to carrier depending on several factors, but on average they are somewhere between 600Kb/s and 1,400Kb/s.

In the case of Sprint, however, they've opted to go the WiMAX route because it was a near-term solution for which the company had enough spectrums to deploy right away. So while the 'real' 4G may still be a long ways off, we'll take all the speed we can get at the moment. Today that's 3-6Mb/s with Clearwire's WiMAX service.

In Nigeria, quite a number of providers offers 4G LTE, MTN, GLO, ETISALAT, AIRTEL are all doing a test runs on the LTE technologies while some few smaller providers including the NATCOM that recently acquired MTEL are rolling out on the LTE technology. VISAfone recently acquired by MTN has an active network on the EV-DO service. The trend is also gaining momentum in Ghana and other West African countries. No operator is offering a WIMAX based 4G service in this region.

We expect operators to maintain their existing 2G or 3G networks for the foreseeable future, to support voice and narrower-band data while providing ubiquitous coverage. WiMAX and LTE will initially be deployed as an overlay network for fast data transfer rates, with multi-mode handsets (EV-DO / WiMAX or HSPA / LTE, for example) enabling users to get the best of both worlds as operators build out their 4G networks over several years.

A Future of Convergence?

As you can guess, today’s debate lies on which technology has the most advantageous position. WiMAX is available now, but even Sprint and Clearwire's highest ranking executives have admitted that LTE might eventually become the dominant 4G technology throughout the world. That's not to say they are fighting an already lost battle. While they believe WiMAX has a lot of potential, and plan to continue pushing it, their decision to back this technology is all about timing. By the time LTE hits the market WiMAX will be available in at least twice as many cities.

On the other hand, GSM network standards dominate over 80% of the cellular markets worldwide, so it's only natural that most mobile operators will want to move to LTE, as it's rooted on the same technology they've worked with for over a decade -- Verizon being the obvious exception with their network based on CDMA standards. Another important factor, as mentioned earlier, is that LTE requires significantly less infrastructure and thus will be cheaper to deploy.

Because both technologies are so similar there has been talk about them converging in the future. Clearwire CEO Bill Morrow emphasized this idea at the recent CTIA Wireless trade show, saying that the wireless industry should focus on the similarities between WiMAX and LTE rather than their differences. Motorola has added to this concept saying that they re-use much of its WiMAX technology when building LTE gear. Morrow envisions both technologies merging into one network standard, but even if that doesn't pan out, he says they can add LTE to their network if necessary.

Verizon was quick to express doubt this will ever happen, but ultimately it's up to the standards bodies and the driving forces behind them. Regardless if such convergence ever gains traction, for now WiMAX is at least a year ahead of LTE in terms of major commercial deployments and is moving full steam ahead. Clearwire will likely market WiMAX devices (and later on WiMAX 2) exclusively for the next 2-3 years, adding an LTE signal with minimal change to its antennas when -- and if -- the market demand is there as the LTE device ecosystem matures. 

Most of the materials used here came from techspot.com