Top Smartphone

Smartphones offer greater functionality than regular cell phones, with the ability to access the Internet, download email, work with document attachments, sync data with personal and corporate computers, send instant messages, play music, show streaming video and scout out locations with GPS - in addition to making phone calls.

Now lets check the top 10 smartphone in market.


1. T-Mobile myTouch 3G Slide

An Android smartphone for first-time users

pros
  • Superb QWERTY keyboard
  • Easy-to-use interface
  • Good call quality
cons
  • Clunky slider mechanism
  • Sub-par camera
  • Weak battery
  
Review:
The T-Mobile MyTouch 3G Slide is an entry-level Android device geared for first-time smartphone users. Reviewers praise its midrange feature set, top-notch QWERTY keyboard and exceptional ease of use. Chris Ziegler at Engadget.com considers it "among the best" QWERTY Android sliders, and CNET's Bonnie Cha says T-Mobile's customized user interface "brings a more consumer-friendly look and feel" to Android. However, experts also say the Slide's features can't compete with powerhouses like the HTC Droid Incredible (Free with contract) or HTC EVO 4G (*Est. $190 with contract). Nevertheless, for those transitioning to smartphones, the MyTouch 3G Slide may be a sound choice.
Thanks to a hardware redesign and a software makeover, the MyTouch 3G Slide is "more than just a re-warmed" MyTouch 3G, says Lisa Gade at MobileTechReview.com. The Slide has a larger 3.4-inch touch-screen display with pinch-to-zoom support, a new QWERTY keyboard and bigger 600 MHz processor. Critics praise the bright, responsive screen, and Kenneth Butler at Laptop Magazine says the QWERTY keyboard "hits the sweet spot." Cha likes its spaciousness, but says the slider can be clunky to open.
The Slide runs on Android OS 2.1 (Eclair) with two user interfaces: one from HTC and the other from T-Mobile, which users say is more user-friendly. In addition to a guided set-up process, the Slide has Android's multi-panel home screen, Google apps and MS Exchange support. The HTC Sense interface adds five customizable home screens and apps like Friendstream, which combines Facebook, Twitter and Flickr updates. The T-Mobile interface features My Modes, which lets you personalize the home screen for work or home, the Faves Gallery (which keeps track of your 20 favorite people), and the Genius button for voice-recognition searching and messaging, a barcode reader and an bundle of recommended apps.
Focus on messaging
For the most part, the enhancements impress reviewers. MobileTechReview.com's Gade says "it's a pleasure to see a midrange phone get the current goods," while PCMag.com's Sascha Segan likes how it focuses on messaging. But Laptop Magazine's Butler says the Motorola Cliq (Free with new contract) does "a better job of integrating social networking."
The Slide is also a good multimedia phone, according to Segan. It includes a standard Android music player, free DoubleTwist syncing software, a 3.5 mm headphone jack and a YouTube video player. While the 5-megapixel camera gets lukewarm reviews for sub-par image quality, the Slide's browser "notched decent page load times," says Butler. Reviewers report excellent call quality with clear volume and reliable 3G coverage, but battery life -- the most common complaint among users at CNET -- falls short of its rated 7.5 hours in tests at CNET, Laptop Magazine and PCMag.
Laptop Magazine's review provides the most complete comparison to rival smartphones such as the Google Nexus One and HTC Evo 4G. Other professional review sources, including MobileTechReview.com and PCMag.com, make fewer comparisons with rival smartphones but nevertheless deliver thorough evaluations, while user reviews at CNET help to illustrate some of the Slide's drawbacks.


2.  T-Mobile Garminfone


An Android smartphone with excellent Garmin GPS

pros
  • Outstanding navigation
  • Navigates even in dead zones
  • Easy user interface
  • Includes dash mount/charger
cons
  • Older version of Android
  • Runs slowly at times
  • Blurry photos and video in some tests
  • May be too basic for advanced users
A phone that combines great Garmin navigation with a smartphone that's at least passable is bound to be a sought-after option. The Android-based T-Mobile Garminfone has its flaws as a smartphone, testers say, but if you want the best possible phone navigation, this is it -- and it's far better than Garmin's last attempt, the widely panned Garmin nuvifone G60 (Free with contract).
Navigation is "fantastic" with the Garminfone, says Tim Stevens at Engadget.com, and other testers agree. While other Android phones such as the Motorola Droid (Free with a new contract) include free turn-by-turn Google Maps Navigation, testers say the Garminfone is a better, more full-featured navigator -- especially since it can navigate regardless of dead zones, unlike the Google Maps version, which must be connected via cell signal to work. The Garminfone comes loaded with North American maps and 6 million points of interest. In a test at Laptop Magazine, it gets a stronger GPS signal than the Droid and is "pretty much identical to a dedicated in-car unit," reviewer Mark Spoonauer says.
Directions in your own voice
The Garminfone speaks directions loudly, its 3.5-inch touch screen is easy to see, and testers appreciate the free dash mount/charger that comes in the box. Free traffic reports, weather information, gas prices and movie times are also included. Reviews say the Garminfone has a couple of neat extra features to play with, too. Garmin Voice Studio allows you to record directions in your own voice. And if a friend sends you a text message with an address in it, you can navigate directly there. The Garminfone even remembers where you parked. "This is brilliant stuff," says Jamie Lendino at PCMag.com.
As for handling calls while navigating, reviews say the Garminfone does a smooth job. When you hit the answer button, the Garminfone switches to speakerphone and mutes its navigation prompts while you're talking, although the screen keeps navigating. Everything switches back to normal once you hang up. Call quality is fine in Laptop Magazine's test, although PCMag.com's Lendino says that while callers sounded clear, they "complained that I sounded a little thin and distant."
Smartphone a bit poky and outdated
Smartphone features are where the Garminfone falters in reviews. It's not as powerful as other Android smartphones, such as the Motorola Droid X. With just 256 MB of RAM, "some operations felt sluggish" in PCMag's test. The Garminfone has 4 GB of memory, expandable via microSD card. It runs the older Android 1.6, not the current version, which means it can't run some of the latest Android apps. On the plus side, testers say the Garminfone's simplified interface makes it easy to use, although advanced users will miss some of the usual Android customizations; Engadget.com's Stevens says this is "not a phone for power users." The touch-screen keyboard with haptic feedback works fine in tests.
Lackluster camera
Web pages load quickly over T-Mobile's 3G network in Laptop Magazine's test -- four seconds for NYTimes.com, five seconds for CNN.com, six seconds for ESPN.com -- although sites without mobile versions take longer. Video and photos range from "decent" to "blurry," with a 3-megapixel camera that lacks a flash that Spoonauer calls "far from the cutting edge." PCMag.coms Jamie Lendino neatly sums up reviewer sentiment: "The Garminfone is the nation's best navigation phone, but there are better choices for a general-purpose smartphone."
Reviews of the Garminfone at Laptop Magazine, PCMag.com and Engadget.com are exceptionally thorough, giving the reader an excellent idea of how the phone performs and how it stacks up against the competition. A video review at CNET expertly critiques the phone and shows it in action.


3.  Motorola Droid 2

Droid 2 incorporates much-needed updates, but offers few new features

pros
  • Android 2.2 improves web browsing
  • Easy, responsive navigation
  • 3G mobile hotspot for up to five devices
  • Improved slide-out keyboard
  • 5-megapixel camera
cons
  • Stiff keyboard buttons
  • Mobile hotspot costs extra
 While it certainly raises the bar for performance and features compared to the original Droid (Free with new contract), the Motorola Droid 2 for Verizon "takes only baby steps forward from the original, struggling to keep up with new titans like the Droid X," says Stewart Wolpin of DigitalTrends.com. What sets the Droid 2 apart is the addition of Android's 2.2 Froyo software, which adds support for Adobe Flash and 3G mobile hotspot capabilities for up to five devices. Hotspot capability will cost you an additional $20 per month for 2 GB of data. Internal changes include an upgrade from a 550 MHz processor to a 1 GHz processor, 512 MB of memory and better battery life (almost 10 hours of talk time, according to PCMag.com tests).
The Android 2.2 "perfectly replicates the desktop experience," PhoneArena.com editors say, thanks to support for the Adobe Flash player. (Most Android smartphones will get this update automatically.) Reviewers praise the Droid 2's toned-down Motoblur interface. PCMag's Sascha Segan says that it's "much less intrusive than Samsung's or HTC's" and will appeal to those looking for a "sparer Android interface." PhoneArena.com calls the Droid 2's screen "nothing that exciting" since the display hasn't changed from the original, but editors are pleased with its responsiveness. Segan rates performance "somewhat faster" than the HTC Droid Incredible (*Est. $80 with new/renewal contract) but "probably be a little slower" than the Samsung Fascinate, another Verizon Android phone.
Responding to complaints about the original Droid, the Droid 2 features a redesigned slide-out QWERTY keyboard that sheds the troublesome D-pad and incorporates bigger, raised keys. It's a bit of a letdown, however, as the keyboard is still "tight" compared to phones such as the Samsung Epic 4G, says PCMag's Sascha Segan, and it still has the "same stiff feeling keys," according to editors at PhoneArena.com. The Droid 2 retains the original Droid's 5-megapixel camera, 720-by-480-pixel video resolution and 3.7-inch TFT capacitive touch screen (854 pixels by 480 pixels). Segan notes that the camera "overexposes shots," though they're still sharp, and finds that the improved 30 frames-per-second video recording (up from 24 fps on the original) presents "smooth and sharp" videos. CNET's Bonnie Cha agrees that pictures are "bright," but feels video quality is "very hazy" even at the highest resolution.


4. Motorola Droid X

Verizon's Droid X leads the Android pack, but may be too big for some

pros
  • Huge 4.3-inch display
  • Roomy virtual keyboard
  • Speedy 1 GHz processor
  • Excellent noise-canceling microphones
  • Long battery life
cons
  • Too big for small hands
  • No front-facing camera for video calling
  • Sluggish Motoblur interface
Everything about the Motorola Droid X is big: its 5-inch chassis, 4.3-inch display, roomy virtual keyboard, fast 1GHz processor and long battery life. "It's a beast, but in a good way," says CNET's Bonnie Cha, while Lisa Gade at MobileTechReview.com calls it "lustworthy." Other reviewers are equally smitten. At PCMag.com, the Droid X snatches the best smartphone crown from the HTC Droid Incredible, while Engadget.com's Chris Ziegler says it "steals the spotlight" from Verizon's other smartphones (such as the Incredible). But David Pogue at The New York Times puts the Droid X's "best" title in perspective: "In this business, the state of the art changes as often as Lady Gaga changes outfits," he says, pointing out that several phones have been proclaimed the "best" Android phone in the past year.
The Droid X is slightly taller than the HTC Evo 4 (*Est. $190 with contract), Sprint's flagship Android phone, but it's a tad lighter thinner. "You feel as if you're talking into a frozen waffle," says Pogue, while Ziegler says it's "definitely not for the small of hands." The huge 4.3-inch touch-screen display appears "truly cinematic," says Gade. It packs a higher resolution and a wider aspect ratio than the Evo (16:9 vs. 5:3), says Ziegler, but experts say the Super AMOLED display on the new Samsung Galaxy S, another Android phone due out this fall, may be tough to beat. The Droid X's spacious virtual QWERTY keyboard has optional Swype technology, which lets you type by sliding from key to key, rather than typing. Critics say it's fast and accurate -- albeit a reach for small hands. Most reviewers say that the Droid X is a great choice for most, but note that users with small hands may prefer the slimmer Droid Incredible (*Est. $150 with new contract).

5.  HTC EVO 4G

4G Android smartphone hits a few speed bumps

pros
  • Huge 4.3-inch display
  • First 4G network device
  • Fast downloads and media streaming
  • Doubles as a personal Wi-Fi hotspot
cons
  • Bulky
  • Limited 4G coverage
  • Extra monthly fees
  • Convoluted video chat app
  • Paltry battery life
The HTC EVO 4G "offers a big, beautiful, and powerful window" to the online world, says Sascha Segan at PCMag.com. As the first 4G (fourth generation) network device in the U.S., the EVO raises the bar with "much faster" web pages, e-mail and skip-free Internet video, says David Pogue at The New York Times. It also touts massive specs: a 4.3-inch display (larger than the iPhone's), hotspot abilities, speech recognition, Flash Lite, dual cameras, video calling, HD video and an HDMI port. Most reviewers regard the EVO as the most powerful Android smartphone, putting it in the pantheon with the HTC Incredible (*Est. $150 with contract) and Apple iPhone 4 (From $200 with contract). Still, the EVO isn't flawless, and Pogue says the "groundbreaking features come with enough fine print to give the White Pages an inferiority complex."
Sprint brands the HTC EVO as the "first" 4G device, even though only 32 metro areas have such coverage and the smartphone switches over to 3G otherwise. The phone uses WiMAX technology to access 4G, but it's solely for data downloads and not phone calls, and WiMAX technology fizzles in urban landscapes. Chris Ziegler at Engadget.com says "we found ourselves getting four bars of 4G walking down the street, then ducking into a coffee shop and dropping to just one or even no bars at all." Sprint also charges EVO owners an additional $10 a month for WiMAX. CNET's Bonnie Cha considers the extra fee reasonable, but says that "making it mandatory for everyone, regardless of whether you live in a 4G market or not, seems unfair."

6.  Apple iPhone 4

Apple iPhone 4 leads the smartphone pack, but not by much

pros
  • Brilliant high-contrast display 
  • Powerful 5-megapixel camera
  • Unrivaled app store
  • Easy FaceTime video calling
cons
  • Limited multitasking
  • Unreliable reception
  • FaceTime restricted to iPhone 4 owners
Reviewers agree the iPhone 4 is the best yet, with huge upgrades to the iPhone 3GS (*Est. $100 with contract). Though its prowess remains undisputed, few critics are willing to peg it the absolute best out there, however. "The iPhone 4 deserves its place in the pantheon of cellphone gods, but as part of a distinguished group, not as a single overlord," says Sascha Segan at PCMag.com. With a level playing field, many critics feel that choosing the right smartphone boils down to a matter of personal preference. "iPhone is no longer the only worthy contender," says David Pogue of The New York Times. The iPhone 4 is available in 16 GB (*Est. $200) and 32 GB (*Est. $300) configurations. 
The buzzworthy feature this time around is FaceTime video calling, which allows you to make face-to-face calls using the VGA camera on the front of the iPhone 4 or the 5-megapixel shooter on back. The technology isn't new, but experts say Apple gets it right. "It's the first phone to make good video calls reliably, with no sign-up or set up, with a single tap," Pogue says, while other critics report it's easier than Android's Fring or Qik apps. However, FaceTime works only on Wi-Fi, and both callers must have an iPhone 4. "That makes FaceTime a special-occasion parlor trick rather than a general purpose solution," says Segan.

Mobile TV

Mobile TV is the latest technology where the TV services are streamed on to the mobile or hand-held devices. Mobile TV is going to get more and more prevalent over the next couple years . There is lot of momentum in the area, even if there are a few commercial products so far.
Already, many mobile operators offer a selection of television channels or individual shows, which are streamed across their third-generation (3G) networks. In South Korea, television is also sent to mobile phones via satellite and terrestrial broadcast networks, which is far more efficient than sending video across mobile networks; similar broadcasts will begin in Japan soon. In Europe, the Italian arm of 3, a mobile operator, recently acquired Canale 7, a television channel, with a view to launching mobile- TV broadcasts in Italy in the second half of 2006. Similar mobile- TV networks will also be built in Finland and America, and are being tested in many other countries.
At the moment, mobile TV is mostly streamed over 3G networks. But sending an individual data stream to each viewer is inefficient and will be unsustainable in the long run if mobile TV takes off. So the general consensus is that 3G streaming is a prelude to the construction of dedicated mobile- TV broadcast networks, which transmit digital TV signals on entirely different frequencies to those used for voice and data. There are three main standards: DVB-H (Digital Video Broadcasting - Handhelds) , favoured in Europe; DMB (Digital Multimedia Broadcasting), which has been adopted in South Korea and Japan; and Media FLO , which is being rolled out in America. Watching TV using any of these technologies requires a TV -capable handset, of course. Among the three technologies, DVB-H was officially adopted by ETSI (the European Telecommunications Standards Institute) as the standard for mobile TV services in Europe.
Just as there are several competing mobile- TV technologies, there are also many possible business models. Mobile operators might choose to build their own mobile- TV broadcast networks; or they could form a consortium and build a shared network; or existing broadcasters could build such networks. Some channels will be given away for free, while others are for paying subscribers only. The outcome will vary from country to country, depending on the regulatory environment and the availability of spectrum. In Italy, 3 bought Canale 7 to get its hands on its spectrum and its broadcaster's licence; in Britain, Finland and America, the scarcity of spectrum makes shared networks most likely.
Among the various mobile TV technologies, the likeliest near-term solution will be to unify under the ETSI-endorsed DVB-H standard. It is considered to be is the best delivery system currently available for most markets, according to many of the operators and vendors.
DVB-H:
DVB-H is a terrestial digital TV standard that uses less power in receiving client than DVB-T (DVB Terrestial), and allows the receiving device to move freely while receiving the transmission, thus making it ideal for mobile phones and haldheld computers to receive digital TV broadcasting over the digiTV network (without using mobile phone networks at all) .
The basic DVB-T television standard has been modified to enable the receivers to be less power hungry, as DVB-T is used in an environment where power consumption is not a major consideration. This power reduction has been achieved by time slicing so that the receiver is only switched on in those time intervals when viewing the channel of interest. These intervals could be anything between a few milliseconds and a few seconds. It therefore reduces power consumption by being switched off for the rest of the time when non-required data is being transmitted. There is therefore a trade off between the data rate required for the service and how much this can be packed into short bursts to save the battery power of the receiver.
Like DMB, DVB-H uses COFDM but with a bandwidth of either 6, 7, or 8 MHz. Additionally it uses a range of different types of modulation from QPSK up to 64QAM and this enables it to have a very high data rate. However it is more susceptible to signal variations and synchronisation problems. Additionally higher transmitter powers are required than those needed for DMB. Also frequencies that are likely to be used have not yet been allocated but it is thought they might be within the existing television bands. The wide RF bandwidth also means that current drain is increased, as wide bandwidth amplifiers are inherently more power hungry.
As it is really just an extension to DVB-T, DVB-H uses the same specs DVB-T. Video is normally encoded with MPEG-2 (but can be encoded with MPEG-1 as well, although very rarely used) and the standard, just like its other siblings DVB-C (Cable) , DVB-S (Satellite) and DVB-T, is mostly used in Europe.
Benefits of DVB-H:
  • An approved standard for handheld equipment by ETSI (European Telecommunications Institute) with a high adoption rate worldwide
  • DVB-H is an open industry standard that was developed by the DVB Project , an industry consortium and is currently being supported by leading companies throughout the wireless industry.
  • It benefits from existing DVB-T infrastructure components, which reduces initial investments in many cases
  • It provides the best user experience in the mobile environment, with an energy saving handset that is only ‘on’ 10% of the time, programme guide, soft handover and in-building coverage
  • It offers an excellent, broadcast-quality picture, because the screen resolution is of a similar standard to VHS
  • Battery consumption is reduced by 90% due to time-slicing technology
  • DVB-H comes from the proven DVB standard used in Europe for standard DTV transmission with a low power mode for battery-powered devices.
  • Efficient use of bandwidth enables up to 55 mobile channels plus scalability
  • It is supported by publicly available air interface specifications helping to drive device interoperability and market development
  • Its security includes end-to-end control of stream encryption, generation of decryption keys and delivery of keys to consumers in a billing-integrated way
  • It will be accessible by an estimated audience of approximately 300 million mobile users by 2006

High Speed Downlink Packet Access (HSDPA)

High Speed Downlink Packet Access (HSDPA) is a packet based technology for W-CDMA downlink with data transmission rates of 4 to 5 times that of current generation 3G networks (UMTS) and 15 times faster than GPRS. The latest release boosts downlink speeds from the current end-user rate of 384 kbps (up to 2 Mbps according to standards) to a maximum value according to standards of 14.4 Mbps. Real life end-user speeds will be in the range of 2 to 3 Mbps.
HSDPA provides a smooth evolutionary path for Universal Mobile Telecommunications System (UMTS) networks to higher data rates and higher capacities, in the same way as Enhanced Data rates for GSM Evolution (EDGE) does in the Global System for Mobile communication (GSM) world. The introduction of shared channels for different users will guarantee that channel resources are used efficiently in the packet domain, and will be less expensive for users than dedicated channels.
HSDPA was introduced in the Third Generation Partnership Project (3GPP) release 5 standards. Assuming comparable cell sizes, it is anticipated that by using multi-code transmission it will be possible to achieve peak data rates of about 10 Mbit/s (the maximum theoretical rate is 14.4 Mbit/s). This will result in a six- to seven-fold throughput increase during an average downlink packet session compared with the Downlink Shared CHannel (DSCH) standards of 3GPP release 99.
3GPP standards beyond release 5 will aim to achieve further throughput increases, say peak data rates in the range 20 to 30 Mbit/s, by using Multiple Input Multiple Output (MIMO) or other antenna array techniques, and possibly asymmetric allocation of frequency spectrum in multi-carrier cells (e.g. a further 100% downlink packet session throughput increase by allocating an additional 5 MHz unpaired band).
HSDPA achieves its performance gains from the following radio features:
  • High speed channels shared both in the code and time domains
  • Adaptive modulation and coding schemes: Quadrature Phase Shift Keying (QPSK) and 16QAM (Quadrature Amplitude Modulation).
  • Hybrid Automatic Repeat reQuest (HARQ) retransmission protocol.
  • Short transmission time interval (TTI)
  • Fast packet scheduling controlled by the Medium Access Control - high speed (MAC-hs) protocol in Node B.
  • Fast scheduling
HSDPA will make life easy for 3G customers, providing vastly better service for both corporate users and individuals, with data delivered at speeds comparable to or better than fixed-line broadband access systems.
  • Corporate users will have easy and secure mobile access to corporate networks, with rapid retrieval and downloading of confidential corporate information.
  • Consumers will enjoy superior quality for video services, including video streaming and gaming.
  • All customers will enjoy fast Web browsing, with rapid access to graphics-heavy Internet sites.
With the availability of HSDPA notebook cards (and a deployed network), the question will be, with ubiquitous HSDPA coverage, will anyone pay for a hotspot service available at only selected locations? There are two possible scenarios where they might. Bandwidth at Wi-Fi hotspots may be hugely price competitive, or even free; and Wi-Fi will come pre-installed on many notebooks. The success of the Intel Centrino platform will see the majority of notebooks ship with in-built WLAN support by the end of 2005, and slotting in an additional wireless card may be overkill for some users. However, with Intel planning to add W-CDMA to Centrino next year, HSDPA may also be on its wireless technology checklist.
As HSDPA settles more into mainstream awareness, we should expect the usual levels of hype to start flying. Already, the technology is being flagged as a potential competitor to DSL, placing a lucrative portion of fixed-line operator customers in the hands of the cellular providers. WiMAX is another opponent being lined-up for a bout with HSDPA. How effectively the 3G upgrade can compete in these arenas will depend on infrastructure cost and coverage density. Regardless, we must admit that the introduction of this new cellular standard has made things a little more interesting.

4G or Fourth Generation Networks

4G or Fourth Generation is future technology for mobile and wireless comunications. It will be the successor for the 3Rd Generation (3G) network technology. Currently 3G networks are under deployement. Approximatly 4G deployments are expected to be seen around 2010 to 2015.
The basic voice was the driver for second-generation mobile and has been a considerable success. Currently , video and TV services are driving forward third generation (3G) deployment. And in the future, low cost, high speed data will drive forward the fourth generation (4G) as short-range communication emerges. Service and application ubiquity, with a high degree of personalization and synchronization between various user appliances, will be another driver. At the same time, it is probable that the radio access network will evolve from a centralized architecture to a distributed one.
The evolution from 3G to 4G will be driven by services that offer better quality (e.g. multimedia, video and sound) thanks to greater bandwidth, more sophistication in the association of a large quantity of information, and improved personalization. Convergence with other network (enterprise, fixed) services will come about through the high session data rate. It will require an always-on connection and a revenue model based on a fixed monthly fee. The impact on network capacity is expected to be significant. Machine-to-machine transmission will involve two basic equipment types: sensors (which measure parameters) and tags (which are generally read/write equipment).
It is expected that users will require high data rates, similar to those on fixed networks, for data and streaming applications. Mobile terminal usage (laptops, Personal digital assistants, handhelds) is expected to grow rapidly as they become more user friendly. Fluid high quality video and network reactivity are important user requirements. Key infrastructure design requirements include: fast response, high session rate, high capacity, low user charges, rapid return on investment for operators, investment that is in line with the growth in demand, and simple autonomous terminals. The infrastructure will be much more distributed than in current deployments, facilitating the introduction of a new source of local traffic: machine-to-machine.

Key 4G technologies:
  • Orthogonal Frequency Division Multiplexing (OFDM)
  • Software Defined Radio (SDR)
  • Multiple-input multiple-output ( MIMO )

Initially DoCoMo planned to introduce 4G services around 2010. Recently DoCoMo announced plans to introduce 4G services from 2006, i.e. four years earlier than previously planned. NTT DoCoMo, Inc. announced that high-speed packet transmission with 1 Gbps data rate in the downlink was achieved successfully in a laboratory experiment using fourth-generation (4G) mobile communication radio access equipments.

The key enablers for the 4G are:
  • Sufficient spectrum, with associated sharing mechanisms.
  • Coverage with two technologies: parent (2G, 3G, WiMAX) for real-time delivery, and discontinuous pico cell for high data rate delivery.
  • Caching technology in the network and terminals.
  • OFDM and MIMO.
  • IP mobility.
  • Multi-technology distributed architecture.
  • Fixed-mobile convergence (for indoor service).
  • Network selection mechanisms.

Internet Protocol Version 6

Internet Protocol Version 6 (IPv6) is a new suite of standard protocols for the network layer of the Internet defined by IETF to replace the current version of Internet Protocol version 4 (IPv4). IPv6 is also called as Next Generation Internet Protocol or IPng.
IPv6 is designed to be an evolutionary step from IPv4. It is a natural increment to IPv4. It can be installed as a normal software upgrade in internet devices and is interoperable with the current IPv4. Its deployment strategy is designed to not have any flag days or other dependencies. IPv6 is designed to run well on high performance networks (e.g. Gigabit Ethernet, OC-12, ATM, etc.) and at the same time still be efficient for low bandwidth networks (e.g. wireless). In addition, it provides a platform for new internet functionality that will be required in the near future.
IPv6 describes rules for three types of addressing: unicast (one host to one other host), anycast (one host to the nearest of multiple hosts), and multicast (one host to multiple hosts). Additional advantages of IPv6 are:
  • Options are specified in an extension to the header that is examined only at the destination, thus speeding up overall network performance.
  • The introduction of an "anycast" address provides the possibility of sending a message to the nearest of several possible gateway hosts with the idea that any one of them can manage the forwarding of the packet to others. Anycast messages can be used to update routing tables along the line.
  • Packets can be identified as belonging to a particular "flow" so that packets that are part of a multimedia presentation that needs to arrive in "real time" can be provided a higher quality-of-service relative to other customers.
  • The IPv6 header now includes extensions that allow a packet to specify a mechanism for authenticating its origin, for ensuring data integrity, and for ensuring privacy.

IPv6 Features:
  • New header format
  • Large address space
  • Efficient and hierarchical addressing and faster routing infrastructure
  • Stateless and stateful address configuration
  • Mobile support (Mobile IPv6)
  • Built-in network layer security
  • Better support for QoS
  • New protocol for neighboring node interaction
  • Extensibility

Addressing Format :
An IPv4 address is a 32-bit value that's usually written in "dotted quad" representation, where each "quad" represents a byte value between 0 and 255, for example:
127.0.0.1
This allows a theoretical number of 2^32 or ~4 billion hosts to be connected on the Internet. Due to grouping, not all addresses are available today.
IPv6 addresses use 128-bit technology, which results in 2^128 theoretically addressable hosts. This allows a really big number of machines to be addressed, and it will fit all today's requirements plus PDAs, cell phones, and even IP phones in the near future without any sweat. When writing IPv6 addresses, they are usually divided into groups of 16 bits written as four hex digits, and the groups are separated by colons. An example is:
fe80::2a0:d2ff:fea5:e9f5
This shows a special thing -- a number of consecutive zeros can be abbreviated by a single "::" once in the v6 number. The above address is thus equivalent to fe80:0:00:000:2a0:d2ff:fea5:e9f5 -- leading zeros within groups can be omitted.

Mobile IPv6:
Mobile IPv6 allows an IPv6 node to be mobile - to arbitrarily change its location on an IPv6 network - and still maintain existing connections. When an IPv6 node changes its location, it might also change its link. When an IPv6 node changes its link, its IPv6 address might also change in order to maintain connectivity. There are mechanisms to allow for the change in addresses when moving to a different link, such as stateful and stateless address autoconfiguration for IPv6. However, when the address changes, the existing connections of the mobile node that are using the address assigned from the previously connected link cannot be maintained and are ungracefully terminated. The key benefit of Mobile IPv6 is that even though the mobile node changes locations and addresses, the existing connections through which the mobile node is communicating are maintained.