Cập nhật tình hình thị trường bất động sản, địa ốc hiện nay tại Việt Nam. Tìm hiểu về bất động sản, thị trường nhà đất, bất động sản Việt Nam.Cnlax.com
Wednesday, August 29, 2007
More on Continuous Packet Connectivity (CPC)
Before i could begin writing some more details on CPC, i came across Martin's Blog which have excellent information on this topic. So i have listed them down here:
Continuous Packet Connectivity (CPC) Is Not Sexy - Part 1
Continuous Packet Connectivity (CPC) Is Not Sexy - Part 2
Continuous Packet Connectivity (CPC) Is Not Sexy - Part 3
There might be a part 3 coming soon, which will make life simpler for people like . Any additional information in form of comments most welcome.
Added on the 14th of Jan 2009.
Part 3 has now added to the same post...
Monday, August 27, 2007
WiMAX on display
Vodafone has deployed WiMAX technology in Malta. The island (population 400,000) is one of Vodafone's smallest markets.
The supplier of the network, Airspan, announced in June that Vodafone Malta had deployed its HiperMAX 80216d 'fixed' WiMAX base stations and CPE to offer bundled mobile, fixed voice, and data services to residential and business customers. Since that announcement was made, Vodafone has joined the lead industry organisation promoting and steering WiMAX development, the WiMAX Forum.
According to Pyramid research, "Vodafone, owing to its scale, is an agent of change in the operator community and we expect others to follow its trajectory. With operators present in different markets and looking for new revenue sources, there is no 'one-size-fits-all' technology, but the wrong technology can set an operator back years."
The research firm adds that "in catering to the needs of different markets and customer segments, operator networks will comprise diverse access technologies, each optimised for certain geographies, demographics, and services. For the WiMAX champions this is good news; for LTE backers it is a strong warning that should lead to increased R&D budgets for the next few years—in both camps.
In other news, Samsung Electronics will demonstrate the next generation telecommunications technologies at its annual international forum, which will shed light on what they call as global 4G technologies and gadgets.
This year’s Samsung 4G Forum will draw more than 130 influential industry leaders and service providers from 26 countries. It will mark the first time that all three candidate 4G technology _ IEEE 802.16m (Mobile WiMAX), 3GPP2 Ultra Mobile Broadband (UMB) and 3GPP Long Term Evolution (LTE) _ will be seen with each other.Each of the 4G technologies has a head cheerleader, with Intel supporting WiMAX, Ericsson touting LTE and Qualcomm preferring UMB. IEEE 802.16m WiMAX, UMB and LTE are expected to be initially implemented in 2010.
I think for companies like Samsung to break into new markets, its very important to use the term 4G. Lets hope that they all succeed.
Saturday, August 25, 2007
Mobile TV via Satellite
A heading of news article yesterday read: "European mobile operators are looking for economic ways of launching broadcast mobile TV services directly to handsets". This made me wonder, if there is a strong case for Mobile TV via Satellite?
Couple of days back, 3 Italia reported that it had 719,000 people using its DVB-H service by August 22, which is about 9.4 percent of its 7.68 million customer base reports Dow Jones in Italian. The figure is a good sign—at the beginning of June it was 600,000 and back in March it was 250,000, or about 3.7 percent of the subscriber base. So this proves that some people are using Mobile TV if available.
The only popular satellite Mobile TV i am aware of being used practically (please correct me if you know more) is the S-DMB being used in Korea.
According to a report in Moconews, currently some 7 million people in S. Korea are watching mobile TV--that equates to one in every seven residents of the country--but none of the operators offering DMB services has yet to make any money. Each of the six terrestrial DMB operators has piled up an accumulated loss of between $22 million and $33 million. The only mobile TV operator that charges for its service is SK Telecom-owned TU Media, which offers its DMB service over a satellite-based system (S-DMB). It has 1.2 million paid subscribers, but TU says it needs at least 2.5 million to break even in operation. That’s before it can even start to recoup its $435 million investment in satellites and networks.
The European Space Agency (ESA) has joined the DVB-H party by funding development of technologies for broadcasting TV to mobiles via satellite. ESA has called its standard DVB-SH (Digital Video Broadcast - Satellite, Handheld) and envisages using satellites to send out video at 2GHz to 4GHz (S-Band). Terrestrial repeaters would be used to give indoor coverage. Eutelsat has commissioned a new satellite to be launched in 2009, with the intention of broadcasting DVB-SHb - though it's hedging its bets by claiming it's for multimedia distribution rather than any specific technology or application. Much of the technology needed by DVB-SH doesn't yet exist, so the ESA will be issuing invitations to tender (ITT) for companies that want to have a go at developing them. First up will be a mobile chipset capable of receiving and decoding DVB-SH version b signals. The ITT is due to be published in the next few months.
Finally i found a good report on BetaNews detailing the pros and cons of Satellite Mobile TV:
It's an ambitious idea, and it's not nearly a done deal. But yesterday, a proposal was introduced before the European Parliament for a timetable by which the EU would select a few choice service providers, for the precious and narrow spectrum it will be making available for the entire continent. It will require the consent and cooperation of all 27 member states - something the EU rarely gets even with less ambitious proposals.
Here's what it means: Last February, the EU established two small chunks of radio spectrum - 1980-2010 MHz and 2170-2200 MHz - as reserve space for future MSS broadcasting. Under normal EU law, member states would each have the right to select their own service providers for satellite TV and radio service for their respective countries. In fact, if the EU were to change its mind now and do nothing, that's what EU states would do next.
But there's two big problems: First of all, no single EU country is very big, geographically speaking, compared to the whole of Europe. A satellite signal covers a very broad portion of the Earth, so any service provider licensed for, say, France could probably have its signal picked up in southern Finland. Simply put, the laws of physics dictate a wide coverage area that technology cannot circumvent...unless every mobile TV receiver in Europe were custom-built for each member country. (If you're thinking like a manufacturer of DVD consoles, you might not be too opposed to trying that.)
Even if France's signal and England's and Bulgaria's and all the others could be picked up everywhere else - which, if you think about it, will be the case anyway - Bulgaria's service provider wouldn't want its signal overlapping England's. And that leads us to the second big problem: There's not enough MSS spectrum available in the 2 GHz band to go around.
So the European Union is stepping in, or at least attempting to. But in order for member states to allow it to do so, it has to formally present its case to those states for why it has the authority to do so. Imagine if, under a different style of US constitution, in order for the federal government to make its case for regulating the public airwaves, it had to get all 50 states' consent to giving up their own rights to do so individually.
Thus a large part of the EU proposal yesterday explains - as it must do under European law - why it's claiming the authority to propose a national selection process for MSS providers.
For its claim to qualify as valid, it has to meet two tests under the EU constitution. First, the claim must meet the Subsidiarity Principle: essentially, that the nature of the job at hand means it can be performed better by the EU than by all the 27 states acting independently. In other words, the EU has to prove it can do the job not because it's better at these sorts of things, but because the problem at hand makes a single body better suited to the task.
Here is where the EU has physics on its side: Satellite signals cover broad territory, and states' boundaries do not. "Selection and issuance of rights over the same spectrum to different satellite operators in different Member States would prevent satellites from covering their natural footprint," the EU proposal reads, "which by nature covers a large number of countries; it would risk fragmenting the satellite communications market and eliminate the natural advantage of satellites compared to other modes of communication. The mobile character of the services involved also means that citizens travelling in the EU should benefit from the availability of such services throughout the EU."
Second, the EU's case must meet the Proportionality Principle. This means it can't claim more authority than it needs to do the job...and once the job is done, it steps out of the way. In other words, it can't appoint a permanent commission like the FCC.
In making that part of the case, the EU goes on, "The proposal will create a mechanism for coordinating the selection and definition of certain conditions to be attached to rights of use of spectrum. It will not touch upon the right of Member States to grant the authorizations to use the spectrum or to attach specific conditions applying to the provision of services in areas which are not harmonized. Member States will be closely involved in elaborating the details of the selection procedure."
Here is where critics say the EU's case may fall apart. In order to win the authority to drive the MSS adoption process, the EU is limiting itself to driving the selection process for prospective service providers. Once that job is done, it's leaving it up to member states to apportion per-country licenses to those companies, for channels which the EU would already have selected as well.
On the one hand, it doesn't make sense. In order to sell its plan, the EU is leaving open the option for member states to deny licenses. But assuming a state does so, how could it block the reception of a signal from a service provider whose license was denied? That might take a technological solution...which brings up the whole "per-country" manufacturing option for MSS receivers again.
On the other hand, only such a hare-brained scheme might just work, because member states don't want to be perceived by their citizens as ceding any part of their authority to a federal institution. Giving them the right to say "no" could be a kind of ceremonial concession, not unlike the establishment of a constitutional monarchy where the monarch is essentially a face on a coin - which is a state of affairs not unfamiliar to member states.
"Since industry so far could not agree on a single standard for mobile TV, commercial launches of mobile TV are delayed," reads a statement from the EU's central authority in Brussels last month. "Europe's competitors, most notably from Asia, have made significant progress - partly due to state intervention - and Europe risks losing its competitive edge unless sufficient momentum is achieved. This is why there is a need to develop a 'blueprint' for mobile TV in Europe."
Is UMB the same as LTE
Recently i have come across press releases trying to sell UMB (Ultra Mobile Broadband) as 4G technology. This is the same as trying to sell LTE and mobile -WiMAX as a 4G technology.
IMT has taken a clever approach and instead of calling the successor of 3G as 4G, they are calling it IMT-Advanced.
The main requirements for 4G are as follows:
- Peak data rate of 100Mbps for high mobility applications such as mobile access
- Approx. 1Gbps for low mobility applications such as nomadic/local wireless access
Doing some digging on the UMB topic, i realised that it is the same as LTE but an evolution from CDMA2000. This is being standardised by 3GPP2.
Some of the key features (and comparing it with LTE) includes:
- It used OFDMA based air interface (same as LTE)
- It supports FDD (LTE supports FDD and TDD and a combination of them so i am not sure if UMB only supports FDD)
- Scalable b/w of 1.25MHz to 20MHz (same as LTE)
- MIMO and Beamforming (Same as LTE but UMB also supports 4x4 antennas whereas LTE supports 2x2)
- Data speeds upto 275Mbps in DL and 75Mbps in UL (LTE has 144Mbps in DL and 57Mbps in UL but that is because of 2x2 MIMO)
Since the term 4G is already being abused so much, one option is to let people use 4G as they wish and then when IMT-Advanced is available, start calling it 5G. What do you think?
Tuesday, August 21, 2007
XOHM = ZOOM + ROAM
The first cities to experience XOHM will be Chicago, Baltimore, and Washington when they get their hands on the soft launch at the end of this year. The full commercial WiMAX launch is scheduled for "the first half of 2008."
Prepare for WiMAX 2.0
I was completely unaware of IEEE 802.16m which is promising speeds upto 1Gbps. Only when someone asked me what my opinion was on this i did some digging in this.
IEEE 802.16m promises to deliver speeds up to 1Gbps and be backward compatible with 802.16e-2005 (mobile WiMAX) solutions. The 802.16m group should wrap up the technology development phase in 2007. Similar to existing mobile WiMAX, 802.16m will use multiple-input/multiple-output (MIMO) antenna technology. The idea with 802.16m, though, is to increase bandwidth by using larger MIMO antenna arrays.
The 802.1m group is targeting ratification and finalization of the standard by late 2009. So, we’re still a couple of years (or more) from having a gigabit version of WiMAX. As compared to other IEEE 802 standards development, such as 802.11, this is an aggressive schedule. In my opinion, these will be difficult dates to hit, especially with the requirement for being backward compatible with 802.16e-2005.
The advantage of 802.11m to cellular companies is that it could allow the convergence of 3G and 802.16 into a single 4G technology for mobile and fixed applications. This would enable cellular companies to offer service, such as IPTV and VoIP, as effectively over wireless connections as they are today on wired networks. This would lead to competition with existing fixed wireless broadband services currently delivered over cable and telephone lines.
Many vendor sources however, have expressed some skepticism about the speed with the work can be completed (the end of 2009 is being mooted as a baked date) and the chances of maintaining backwards compatibility with mobile 802.16 technology. Some folks worry that carriers have unrealistic expectations on how fast new WiMax profiles and interfaces can be developed. "They just walk in, snap their fingers, and expect it to happen," one industry source told us on the show floor yesterday. After all, it took several years for the IEEE to arrive at a satisfactory fixed broadband wireless specification in the form of 802.16d and even longer for the WiMAX Forum to certify interoperability between products using the technology.
Martin has some interesting analysis on his Mobile technology page:
Between today and WiMAX II, there's systems such as WiMAX and LTE which promise faster data rates than those available today by mainly doing the following:
- Increase the channel bandwidth: HSDPA uses a 5 MHz channel today. WiMAX and LTE have flexible channel bandwidths from 1.25 to 20 MHz (Note: The fastest WiMAX profile currently only uses a 10 MHz channel today for the simple reason that 20 MHz of spectrum is hard to come by). So by using a channel that is four times as broad as today, data rates can be increased four times.
- Multiple Input, Multiple Output (MIMO): Here, multiple antennas at both the transmitting and receiving end are used to send independent data streams over each antenna. This is possible as signals bounce of buildings, trees and other obstacles and thus form independent data paths. Both LTE and WiMAX currently foresee 2 transmitting and 2 receiving antennas (2x2 Mimo). In the best case this doubles data rates.
- Higher Order Modulation: While HSDPA uses 16QAM modulation that packs 4 bits into a single transmission step, WiMAX and LTE will use 64QAM modulation under ideal transmission conditions which packs 6 bits into a single transmission step.
here and especially here):
- Again increase of the channel bandwidth: They use a 100 MHz channel for their system. That's 4 times wider than the biggest channel bandwidth foreseen for LTE and 20 times wider than used for today's HSDPA. Note that in practice it might be quite difficult to find such large channels in the already congested radio bands.
- 12x12 MIMO: Instead of 2 transmit and receive antennas, DoCoMo uses 12 for their experiments. Current designers of mobile devices already have a lot of trouble finding space for 2 antennas so a 12x12 system should be a bit tricky to put into small devices.
- A new modulation scheme: VSF spread OFDM. This one's a bit mind bogelling using CDMA and OFDM in combination.
More Information available at IEEE 802.16 Task Group m (TGm) page.
Saturday, August 18, 2007
GSM/UMTS Growing faster than other technologies
A total of 564.6 million new subscriptions to GSM/UMTS services worldwide in the twelve months ending in June, with almost 18% of these from the Western Hemisphere alone, according to the estimates of Informa's World Cellular Information Service. GSM/UMTS added nearly 100 million subscriptions in the Americas during this time period, more new subscriptions than any other technology. GSM/UMTS continues to lead the wireless market of Latin America and the Caribbean, where nearly 22 million GSM users were added in 2Q 2007, increasing GSM market share in the region to 74%.
GSM is not only the leading industry standard for reliable wireless voice communication with more than 2.5 billion customers, but also plays an integral role in 3G as more than two thirds of the estimated 200 million 3G users across the globe use UMTS/HSPA technology for mobile broadband. There are currently 181 UMTS operators in service across 77 countries, with an additional 72 networks planned, in deployment, or in trial. Of those 181 operators, 135 have enhanced service with HSDPA, with 80 additional HSDPA networks planned. Five operators across the world have launched HSUPA technology to date, and over 130 more operators plan to upgrade with HSUPA, many in the second half of 2007.
GSM technologies account for 85% of mobile wireless customers globally. More than half a billion new subscriptions to the GSM family in the past twelve months ending June 2007 represent a worldwide growth rate of 29.5%. Focusing on the Western Hemisphere, GSM holds nearly a 60% share of market, with a subscriber base of 358 million GSM/UMTS customers, compared to 191 million for CDMA. In Latin America and the Caribbean, there are 340 million total wireless users, and of these, 253 million use GSM, which now holds a market share of 74% in the region, up from 62% one year ago.
Erasmo Rojas, Director of Latin America and the Caribbean for 3G Americas stated, “The growth in the uptake of GSM/EDGE/UMTS technologies in Latin America continues to progress. Wireless service providers are achieving great results in increased contribution to their Average Revenue Per User (ARPU) from wireless data services through their deployment of EDGE and now recently UMTS/HSDPA.” He continued, “As of June 2007, typical operator ARPU from wireless data value-added services represents more than 15% of total wireless revenue in countries such as Mexico (15%), Ecuador (20%), Argentina (24%) and Venezuela (24%).”
To view the latest statistics on wireless growth, visit the 3G Americas website at: http://www.3gamericas.org/English/Statistics/.
Friday, August 17, 2007
'3' starts MBMS trials
MBMS uses existing 3G networks and spectrum for content delivery, building on existing infrastructure. To deliver MBMS, upgrades are made to the existing network as well as content and broadcast servers. 3G mobile phones with support for MBMS are expected to be available in 2008, said the company.
MBMS is a different approach to Mobile TV combining both broadcast and unicast shows (though multicast is more accurate). It also gives consumers opportunity to interact by voting, sending messages, accessing downloads of related content and special promotions from advertisers.
"MBMS as part of the 3G evolution is an attractive technology not only because of its flexibility and efficiency, but because it's quick and easy to deploy and leverages existing infrastructure," said Kursten Leins, Strategic Marketing Manager - Multimedia, Ericsson. "MBMS allows an unlimited number of users to watch the same mobile TV program at the same time in the same area, as well as enabling valuable user interaction with advertisements, campaigns and programs."
"3 pioneered 3G in Australia, so it was a great opportunity to see the country's first MBMS technology trial run on Australia's first 3G network," Leins added. Since the MBMS signal can be pin pointed to specific geographies, it's also possible to broadcast different mobile TV programs to different areas, giving a locally-specific customer experience and also providing highly targeted mobile advertising opportunities.
"The trial has been very interesting, and we'll continue to work with Ericsson to keep a close eye on the technology and the handsets to support MBMS as they develop," Young added.
Thursday, August 16, 2007
FMC: Fixed Mobile Convergence
FMC will enable single device to perform myriad functions. The main points of interest are:
Dynamic increase of IP based services especially driven by fixed access
VoIP replaces circuit switched service in fixed networks
VoIP will replace circuit switched voice in mobile networks
The border between fixed and mobile networks dissapears
Source: LTE from a handset perspective, LG Electronics, 'LTE 2007', May 2007
Monday, August 13, 2007
Beginning of the Cablefree world
With UWB becoming popular and more devices about to be rolled out, the cable connections between TV, VCR, DVD players, Camcorders, etc can be a thing of past.
In UK, OFCOM removed the restrictions for the use of UWB devices upto a range of 30 metres. In the US and Japan, UWB home hubs are a popular way of sharing domestic broadband.
Ultra-Wideband (UWB) can be used to send huge amounts of information between electronic devices, making it suitable for connecting items such as digital TV decoders and DVD players to television sets, or digital cameras to computers.
It could also be used to wirelessly link satellite dishes or cable TV connections to set-top boxes, doing away with the need for cables to be poked through walls and run around skirting boards. Satellite broadcaster Sky, for instance, is understood to be looking at whether UWB could be integrated into its equipment.
Described by techies as "Bluetooth on steroids", UWB can operate over distances of up to 30 metres. Japanese electronics manufacturers are already producing modems that use UWB, while Cambridge-based chip maker ARM Holdings has deals with several companies that plan to make UWB devices.
Separately, Vodafone yesterday joined the Wimax Forum which is creating standards and specifications for a new longer-range wireless broadband technology. The company stressed that it is taking a neutral stance on the next generation of wireless technologies, but the move raised eyebrows in the mobile phone industry.
Wimax, which can operate over many miles, is seen as a competitor to another next generation wireless technology, which is being developed by the mobile phone companies and builds on the existing 3G standard. LTE, or Long Term Evolution, is an mobile industry-led project designed to upgrade the existing 3G service. The LTE group is supposed to come up with recommendations on a new standard next month.
Earlier this year Vodafone's chief executive Arun Sarin warned that the process of getting a new wireless standard was taking too long. "As an industry it takes us a long time to get things done - we need to move faster or others will eat our lunch," he said.
Meanwhile The European Commission is opening up the wireless technology market by discarding out-dated rules limiting the areas of available radio spectrum. Next-generation wireless technologies such as BlackBerrys and smartphones work best over low frequencies that, until now, were reserved for GSM mobile phones. According to a statement last week, the Commission will allow new services to co-exist alongside GSM. The aim is to establish a more flexible, market-driven approach to spectrum management, says European Union telecoms commissioner Viviane Reding.
Sunday, August 12, 2007
Training on Latest 3G/4G Topics
High Speed Uplink Packet Access (HSUPA) - 1 day
High Speed Packet Access (HSPA/HSPA+) - 2 days
Introduction to MBMS - ½ day
MBMS and Mobile TV - 1 day
Advanced MBMS - 1-2 day(s)
IP Multimedia Subsystem (IMS) - 2 days
Robust Header Compression (RoHC) - ½ day
Long Term Evolution (LTE) - 1 day
TCP/IP Refresher Course - 1 day
TCP/IP Overview for Telecom Engineers - 2 days
WiMAX and 4G Wireless - 1 day
New Wireless PAN (WPAN) Standards - 1 day
Thursday, August 9, 2007
Vodafone plays the WiMAX card
WiMAX standard is often compared to Wi-Fi, though the comparison is unfair as WiMAX isn't based on a 20-year-old wired standard but was designed for wireless use (at least, the bits not borrowed from DOCSIS were). WiMAX offers greater speed and range than Wi-Fi, but most importantly it offers quality of service guarantees that make VoIP and streaming applications easier to manage.
"Our membership of the WiMAX Forum will complement our existing memberships of other key industry bodies such as the GSMA, 3GPP, and the Next Generation Mobile Network initiative," Vodafone global chief technology officer Steve Pusey said.
WiMAX has been heavily pushed by Intel, which intends to build it into laptop chipsets, encouraging rapid adoption of a technology in which it owns key intellectual property.
According to Ovum analysis:
Although a slightly crude generalisation, it's basically accurate to see the WiMAX Forum as the wireless Internet camp; the 3GPP as the wireless telecoms camp. There was a time when those two camps represented philosophies which were mutually exclusive and frequently antagonistic. These days, it makes less sense to see the world in those terms, because convergence between telecoms and the Internet - though far from complete - is now well under way. But at this early phase of the transition to convergence, it's not yet clear whether the predominant technologies and business models will eventually be those of telecoms, or those of the Internet. It's sensible, therefore, to remain interested in (and influential over) both possible outcomes, so long as they both remain possible.
Tuesday, August 7, 2007
Which Mobile TV technology to go for?
A recent survey shows more than 40 percent of cell phone users in China like the idea of watching TV on handsets. Some pundits even predict the number of mobile TV users in China will jump to nearly 60 million in 2008, and revenue from handset sales and programming will generate 1.3 billion yuan (US$170m).
The road to mobile TV, however, most likely will be bumpy. Current trials have found several vulnerabilities, such as handset display hang-up when video content is loaded, short battery life and overheating, that must be fixed.
What’s really hindering mobile TV development in China (and, arguably, in other geographical regions), however, is lack of agreement on one standard. In June, a government agency overseeing the mobile TV industry reaffirmed CMMB (China Mobile Multimedia Broadcasting) as the official standard for 3G video service. The reason: CMMB is homegrown and completely free of foreign IPRs.
The State Administration of Radio, Film and TV developed CMMB last October, but a tug-of-war over the standard has undermined SARFT’s efforts to implement it this year. Despite a slow start, SARFT has obtained 25MHz in bandwidth on 2.5GHz for CMMB service and plans to build networks for the Olympics in six cities, including Beijing, Shanghai and Qingdao.
The other contenders CMMB must fight are DVB-H (Europe), Media-FLO (United States), T-DMB (Korea), DMB-TH (a digital TV spec modified for handheld developed by Tsinghua University), T-MMB (Nufrontsoft, which is aligned with MII, the Chinese telecom regulatory body) and CMB (Huawei).
For now, CMMB appears to be most appealing because of SARFT backing. SARFT’s control of programming and distribution in China gives CMMB a huge regulatory and cost advantage over rival mobile TV standards.
Recognizing that CMMB has clout in China, a large industry alliance of 120 companies backs the standard, including heavyweights such as Nokia, Motorola and Sony Ericsson, and Chinese firms like Lenovo, Huawei and ZTE.
One of the main benefits of CMMB, according to SARFT, is that it does not charge royalties for two years, saving an estimated 1 billion yuan (US$130m) in foreign IPR payments. SARFT hopes the savings will encourage handset manufacturers to cooperate in perfecting the standard and expediting proliferation.
There are other concerns. Some Chinese standards are not really independent but a hodgepodge of foreign versions. Reports say T-MMB, developed by Nufrontsoft, incorporates certain core DAB patents like DMB that will be in effect until 2013. Critics say if Chinese handset makers adopt T-MMB they will have to dole out hefty royalties–about US$6 per set or up to US$120m to US$300m per year.
CMMB and T-MMB use different approaches to video transmission and delivery. T-MMB uses a streaming overlay on top of mobile infrastructure, so that it shares the total bandwidth and download speed for the service, like the current video service. CMMB relies on a tuner installed in the handset to receive video signals over the air.
The T-MMB advocates say adding a tuner will compromise other features affecting handset and overall performance, while the CMMB supporters predict T-MMB will be dead on arrival because video traffic will crash the network and cost will skyrocket.
The debate over mobile TV standards is not just about patriotism and technology. SARFT has jurisdiction over broadcasting via various media outlets, including handheld devices, while T-MMB is a brainchild of MII which, by default, only provides a transmission conduit to end users but not content and distribution.
The problem is that both sides see mobile TV as a golden opportunity but want to run the market on their own terms. At this time, the central government sees it as a market issue and is reluctant to provide guidelines, so tussle over mobile TV probably will go on for some time before technical issues are straightened out.
Monday, August 6, 2007
UMA is not Dead
Because femtocells do not use WiFi signals, they don't require dual-mode handsets, which opens up the market to customers that don't want to ditch their current phones just to get the benefits of a stronger in-home signal. Meanwhile, potential T-mobile HotSpot@Home customers can only choose between two phones (the Nokia 6086 and Samsung T409), which means existing customers have to ditch their current mobile phones for a dual-mode device. Blackberry 8820 will soon be available in U.S. which has support of UMA.
"The femtocell industry is starting to appreciate the three year head startOne thing to remember here is that not all mobiles supporting WiFi will support UMA. On the other hand all phones that support UMA will support WiFi.
UMA has over proprietary approaches being proposed for device-to-core network connectivity," said Patrick Tao, Kineto's vice president of technology. "As the
technology behind successful l dual-mode handset services, such as unik from
FT/Orange and T-Mobile's Hotspot @Home, the 3GPP UMA standard has already identified and addressed the real-world deployment issues operators face in
bringing femtocells to market. These issues include security, device
authentication, access controls, handover, regulatory compliance, as well as
scalability to support millions of endpoints."
Friday, August 3, 2007
Certified Wireless USB is finally here
Two manufacturers of laptop PCs and two designers of wireless hubs and adapters are the first companies to receive consumer product certifications from the Universal Serial Bus Implementers Forum (USB-IF). The Certified Wireless USB products are expected to be in stores for the back-to-school and holiday gift season.
Previously certified silicon from Alereon, Intel Corp., NEC Corp., Realtek Corp., and WiQuest Communications are integrated into the products, according to the USB-IF.
The two laptop companies are Dell Computer for its Inspiron 1720 notebook and Lenovo for its ThinkPad T61/T61p 15.4-inch Widescreen Notebook. Networking companies D-Link and IOGear each had a wireless hub and also an adapter certified. Certification of the Wireless USB protocol by the USB-IF assures the interoperability of devices from a variety of manufacturers.
Certified Wireless USB is based on the WiMedia Alliance's Ultra-WideBand (UWB) common radio platform, which is capable of PHY-layer data rates of 480 Mbit/s at distances up to 3 meters and 110 Mbit/s at up to 10 meters.
From an engineering perspective, the question of co-existence with other wireless technologies in the 3 GHz band has been a persistent question for Wireless USB.
Dell and Lenovo have announced the first notebooks with embedded Certified Wireless USB chips - the Dell Inspiron 1720 and Lenovo ThinkPad T61and T62p. The laptops connect wirelessly to USB peripherals hooked up to Certified Wireless USB hubs such as those released by D-Link and IOGear. They will carry a Certified Wireless USB logo. In the interim, until peripherals catch up with the technology, they will need to be plugged into a wireless USB hub. This will allow the Dell and Lenovo laptops to communicate with a peripheral device such as a conventional printer plugged into the hub.