Friday, 15 May 2009
Golden-i: Futuristic Bluetooth Headset with Virtual PC Display
Thursday, 14 May 2009
Inter symbol and inter carrier interference (ISI and ICI) in OFDMA
- Large scale fading: It is the fluctuation in the average signal strength over a large distance and is caused by terrestrial change. This occurs when a mobile travel from a lake to mountainous are to a lake area or from an open area to a tall buildings area. Large scale fading can be mitigated by controlling the transmit power.
- Small scale fading: Occurs as a result of the fluctuations in the received signal strength over a small distance and is caused by multipath and Doppler's shift. Doppler shift refers to the change on frequency of the signal because of relative motion between the transmitter and the receiver.
The figure here shows the multipath propagation for a signal. Signal goes from transmitter to the receiver through multipath that have different lengths i.e. path 1, path2 and path 3. The signal from different path arrives at the receiver at different times although it’s originated from the same source. The received symbol as shown below is longer than the duration of the original symbol.
Delay spread can cause adjacent symbols to interfere at the receiver. As a result of the multipath the delayed version of the first symbol shifts into the next symbol time and thus causes overlap between he symbols. In OFDMA this is taken care of where more time is give for each symbol to be received at the receiver by inserting a guard time.
The Doppler shift introduces another type of interference in OFDMA i.e. inter carrier interference (ICI). OFDMA divided the spectrum into narrowband subcarriers and they are tightly spaced simply because they are orthogonal. One of the requirements for orthogonality is to maintain the subcarrier spacing exactly the reciprocal of the symbol period. The figure below shows the frequency shifts thus changing the subcarrier spacing which results in the loss of orthogonality. This loss of orthogonality creates interference among the signals which is called as ICI. Since the subcarriers in OFDMA are usually very narrow hence the OFDMA system becomes very sensitive to ICI. ICI destroys the orthogonality of the OFDMA system which is overcome by the use of cyclic prefix mechanism.
Under this mechanism OFDM symbols are extended into periodical symbols i.e. redundant information is sent out to ensure that analysis can be conducted on the undistorted information and is called as cyclic extension.
It can be implemented by copying the portion of the original symbol from the end and attaching it to the front or copying it from the front and attaching it to the end. Since OFDMA has already assigned the guard time to defeat ISI, cyclic extension can be put into the guard time interval. This is called cyclic prefix. With cyclic prefix used the delayed version of the previous symbols cannot shift into the useful time of the current symbol so ISI is eliminated as well. Also the cyclic prefix provides redundant information and allows spectral analysis in the receiver to maintain the orthogonality of the subcarriers. Thus the cyclic prefix can be used to deal with both ISI and ICI.
The above concepts can be summarized in teh form of the picture below
Vodafone (JIL) to release new APIs to third parties
Wednesday, 13 May 2009
Surround Sound transmission technology from NTT DoCoMo
NTT DOCOMO, INC. announced that it has developed a highly efficient mobile spatial audio transmission technology that enables a mobile phone user to assign a spatial position to each sound source when listening to multiple sound sources, such as during a game or a conference call.
While existing spatial audio transmission technologies independently process audio encoding/decoding and spatial audio synthesis, the new technology offers a more efficient method by integrating the two processes, thereby minimizing bitrate (or bandwidth) and computation loads suitable for mobile phones and other resource-limited devices.
The processes are collaboratively performed on both the server and client sides. The server identifies the important sound components of each speaker's voice, compresses them efficiently into a single stream and transmits it to the mobile phones. Each phone then decodes the received stream and simultaneously synthesizes spatial audio images
DOCOMO is demonstrating its new spatial audio transmission technology using docomo PRO series™ HT-01A handsets during Wireless Technology Park 2009 at Pacifico Yokohama on May 12 and 13.
Tuesday, 12 May 2009
iPhones in the War Zone
Tying the hands of a person who is speaking, the Arab proverb goes, is akin to "tying his tongue." Western soldiers in Iraq know how important gestures can be when communicating with locals. To close, open and close a fist means "light," but just opening a fist means "bomb." One soldier recently home from Iraq once tried to order an Iraqi man to lie down. To get his point across, the soldier had to demonstrate by stretching out in the dirt. Translation software could help, but what's the best way to make it available in the field?
The U.S. military in the past would give a soldier an electronic handheld device, made at great expense specially for the battlefield, with the latest software. But translation is only one of many software applications soldiers now need. The future of "networked warfare" requires each soldier to be linked electronically to other troops as well as to weapons systems and intelligence sources. Making sense of the reams of data from satellites, drones and ground sensors cries out for a handheld device that is both versatile and easy to use. With their intuitive interfaces, Apple devices—the iPod Touch and, to a lesser extent, the iPhone—are becoming the handhelds of choice.
The sheer versatility of the kit – with the capability of over 30,000 programmes – allows a huge variety of functions needed for operations ranging from providing language translations to the transmitting of sensitive information and working out trajectories for snipers. Projects are on the way to use them as guidance systems for bomb disposal robots and receivers of aerial footage from unmanned drone aircraft.
The US Marine Corps is funding an application that would allow soldiers to upload photographs of detained suspects, along with written reports, into a biometric database. The software would match faces, in theory making it easier to track suspects after they're released.
Members of the British military who have seen the Apple instruments in action drool about the opportunities on offer. The Ministry of Defence, however, remains wary of security implications and has "no plans" at present to go down the American path.
But Lieutenant Colonel Jim Ross, the director of the US Army's intelligence, electronic warfare and sensors operation, believes the iPod "may be all that the personnel need".
"What gives it added advantage is that a lot of them have their own personal ones so they are familiar with them," he said.
Another plus is the cost. The iPod touch (which soldiers can use over a secure WiFi network) retails for around $230 (£150) and the iPhone for $600. Bulk orders placed by the Pentagon bring further savings. The manufacture of a specific military model would be much more expensive.
Robert Emerson, a security analyst who has advised foreign governments on computerised warfare, said: "The US military has had a reputation for being somewhat heavy handed, with justice. But what they are doing with iPods and iPhones show they can also be nimble on their feet. Other militaries should learn to be equally open minded."
Monday, 11 May 2009
What actually are Smartphones?
What Can a Smartphone Do? Unlike traditional cell phones that restrict a user to the applications and features that are originally designed for and then fixed into the phone, Smartphones allow for significant user-customization. These full-fledged operating systems (of which there are several options to choose from) allow a user to customize, install, and configure applications to suit their individual needs. Along with the prerequisite phone capability, Smartphones typically perform all sorts of important and useful tasks.
Smartphones are very smart in personal Information Management (PIM): PIM is a whole category of software functions that organize personal information. A typical PIM suite includes a scheduler for events, and address book for contacts, and to-do list. PIM can also include email, text notes, voice notes, and alarms / reminders.
Syncing with Desktop and Laptop PCs: Many Smartphones are designed to communicate with full-fledged PCs. Aside from just being cool, this feature allows users to easily install, remove, change and configure the software that they choose to equip their Smartphone with. It also allows further synchronization with PIM software both on your phone and on your PC.
Instant Messaging (IM): Not every phone that provides IM capability is a smart phone. But almost every Smartphone has a keyboard that at least allows access to every letter of the alphabet for sending Text messages. Some Smartphones have a key for every letter; others designate several letters per key. Word recognition software and other smart features further improve the speed and accuracy of Text messaging on these kinds of phones.
Email Access: While there are plenty of non-Smartphones that provide internet and email access, this option is more complete (and configurable) on Smartphone devices. You can sync email with your PIM software both on your phone and on your PC, send, read, and organize email, all from your phone. In most cases, you won’t even need to be near a wireless hotspot, either.
Web Browsing: All Smartphones allow for some form of Internet access. Wireless Network Protocols, or the technique in which web information is sent and received over cellular networks, are grouped into different generations.
Smartphones are capable of so many features normally reserved for the realms of PCs and powerful PDA devices because they are almost PCs and PDAs themselves. There are typically two schools of thought used when designing a Smartphone: Create a PDA with Telephone capabilities, or a Telephone with PDA capabilities. No matter what design elements went into Smartphones developmental stages, there are still two things that set these mobile wonders apart from their regular cellphone cousins.
As mentioned above a Smartphone differs from a regular phone in that it has a processor running inside it, much like a computer does. These processors are currently nowhere near the power of PCs, but with the advent and subsequent redesign of Ultra Portable PCs (sometimes called Micro PCs), we are sure to see great leaps in Smartphone speeds in the future. Current Smartphones commonly use ARM processors; a power-efficient design used in other devices like routers, printers, and advanced MP3 players. A Smartphone processor is aided by computer chips that help perform certain tasks. A Smartphone equipped with a Digital Camera has an Image Processing Sensor inside it, much like a regular digital camera. Features like Playing Digital Music, complex web browsing, and other such access smart functions are all made possible by these computer chips.
If Smartphones have Operating Systems (OS), then it stands to reason that they also have software applications, as well. Applications that are written for a specific Smartphone platform (Platform is a fancy reference to the OS) can run on a Smartphone with that particular platform, regardless of what manufacturer produces the phone.
Based on the above discussion there is no doubt the most important software on a Smartphone is the Operating System. This is because nothing will work without it. A Smartphone operating system manages the hardware and software on the device. Some OS cover the entire access Software Stack while others only provide the lower levels like the Kernel and Middleware. These OS versions rely on third party software platforms to provide User Interface Frameworks.There are several different Operating Systems available for Smartphones. Some are designed for manufacturer-specific Smartphones, others are open and can be used on any Smartphone that meets the minimum requirements. Following are some of the OS for the Smartphones.
- Symbian OS: Symbian OS is used in over 100 different makes and models of Smartphone. This Operating System contains only the Kernel and Middleware parts of its software stack. This means that users of the Symbian OS will rely upon other software platforms for the AEE and User Interface Frameworks. This allows significant customization by both Wireless retailers and consumers.
- Linux OS: There is something special about Linux. It is developed and written by the developer community rather than by a single company. This allows for maximum creativity and innovation for developers and those software-savvy consumers, but has one major drawback: it means that software, updates, and other applications written for Linux operating systems differ greatly from each other. This reduces compatibility, and thus originally caused developers to avoid Linux. That is now changing, but many Smartphone manufacturers prefer to stick with more universally accepted OS software.
- Windows Mobile: This is one of the few Smartphone OS that envelops the entire Software Stack. Much of the strengths of Windows mobile lie in its completeness and full compatibility with other Windows based systems.
- Java and Garnet OS
LTE-Advanced Presentations and White Papers
Sunday, 10 May 2009
Powerful search functionality on 3G4G website
Saturday, 9 May 2009
Bluetooth yet to become popular in Japan
Derek Soh is the Bluetooth SIG’s marketing director for APAC and Japan. He agrees with Naudo’s assessment, noting a Millward Brown study that showed only 60 percent of the Japanese population is aware of the technology, versus up to 85 percent elsewhere. This is puzzling, given that Japan has so many companies developing and pushing the technology. According to Soh, among companies represented in the Bluetooth SIG, Japan has the third-highest number of Bluetooth SIG Associate members after the United States and Taiwan, and it boasts the fourth-highest number of Adopter members.
In Europe and the United States, concerns about the health effects of cellphone usage and laws against using mobile handsets while driving fueled the proliferation of wireless headsets. However,in Japan people tend to spend less time driving and more time taking public transit. There is also a cultural preference for mobile text messaging over making voice calls. While the Japanese government enacted stiffer penalties in 2004 for driving while talking on a cell phone, the uptick in Bluetooth enabled headset sales has been modest. “Headsets just don’t appear to be available in as many retail outlets as in other countries,” says Green.
But there is light on the horizon. “The number of Bluetooth enabled handsets in Japan is forecast to grow from just under 20 million—30 to 40 percent of those shipped—in 2007 to over 60 million, 80 percent, in 2013, a CAGR (compound annual growth rate) of 24 percent,” says Naudo.
In addition to more headset use, there are other reasons for the optimistic forecast. “Streaming music services over mobile networks, such as Japan’s Chaku Uta, will be key drivers of Bluetooth inclusion in cellular handsets,” predicts Andy Bae, a senior analyst at New York-based ABI Research.
Bluetooth technology is making inroads in several other Japanese sectors as well. The auto industry is installing the wireless specification in more and more new cars. “Japanese automakers have lagged behind their European and U.S. counterparts in adopting Bluetooth technology, but now they are beginning to catchup,” noted an article in The Nikkei Weekly, a business newspaper published in Tokyo.
Says Green at IMS Research, “We estimate that around 24 million Bluetooth chips were used by automotive companies in 2007,” although he added that “only around 10 percent of cars produced in 2007 had Bluetooth technology built in at the point of production.” That has opened up a new market for after market products like hands-free kits, navigation devices and A/V systems.
Another sector where Bluetooth technology may see further success in Japan is video games. “In 2007, total shipment volume of Bluetooth enabled gaming devices such as the Nintendo Wii and Sony PS3 surpassed that of Bluetooth enabled headsets – amazing!” says Soh.
Finally, several companies, including Toshiba, will begin rolling out Bluetooth low energy enabled devices aspart of a personal health care ecosystem by mid-2009, and many hope this effort will help familiarize Japanese consumers with the technology. (Click here for more on Toshiba and the Japanese health care market.)
With the ongoing updates to the Bluetooth core specification, developers are planning plenty of newproducts featuring the technology. Whether Japanese consumers will bite remains to be seen.
Beau Miller has lived in Tokyo for 17 years and is the editor of Metropolis, Japan’s weekly lifestyle and listings magazine for the English-speaking community.
Friday, 8 May 2009
TD-SCDMA ready to battle other 3G standards
Days ago, it announced the list of 29 types of TD-SCDMA service-built-in netbooks. Such netbooks with six brands like Lenovo, Dell, Haier, Founder, HP will be exclusively sold by the telecom operator. Earlier, it disclosed that it would set aside CNY 650 million to finance TD-SCDMA terminal manufacturers' R&D.
In addition, China Mobile plans to set up a TD-SCDMA industrial park in the eastern Chinese province of Zhejiang before 2011, involving a total investment of CNY 1 billion, said one of its executives.
In the first quarter of 2009, the company achieved operating revenue and net profit of CNY 101.269 billion and CNY 25.201 billion, up 9.2% and 5.2% year on year, citing its financial report.
By the end of March, the number of its subscribers had reached 477.16 million, representing a slowed growth of 19.91 million, due to a demand drop caused by the decelerating macroeconomic, squeezed space for mobile telecoms popularity increase, and intensified competition after a far-reaching asset reshuffle among the country's telecoms operators.
Nokia Siemens Networks and Ericsson Inc each took a 5% share of it.
China Mobile earlier said it plans to build TD-SCDMA networks in 200 Chinese cities by the end of this year.
Such a scenario clearly requires one or more biddable handset partners, and Dell could well step in, alongside various Chinese suppliers, since it would gain such a major springboard for the mobile market via Mobile's huge user base. It would not only have to support the China-specific operating system, though, but would also have to incorporate the TD-SCDMA 3G standard, as well as GSM. Dell will also offer a TD-SCDMA netbook with the launch of its Inspiron Mini 10 in China this week.
According to Zhang, other vendors working on TD-SCDMA/OMS phones include Huawei, ZTE, HTC and Lenovo. The last of these should get to market first with the so-called OPhone.