3/28/2009

SNS enabled by Broadband Mobile Network

Broadband Mobile Network Outlook in Japan

2001 is the first year in which NTT docomo launched its W-CDMA service in Japan firstly of the world. In the following several years, mobile broadband networks (i.e., services offering a minimum speed equal to, or greater than, 256kbit/s in one or both direction) were deployed over the world. The next figure shows top 10 economies by the number of mobile broadband subscribers, in millions, as of the end of 2005.

The two far east countries have been leading on the cutting edge of mobile broadband. Note that those countries have well-established mobile multimedia ecosystems which are independent from PCs’. As i-phone differentiates itself from PC not only in its innovative user interface but also in its mobile application ecosystem, broadband cell-phones in the far east countries have been a kind of premature i-phones for general population from the aspect of the mobile application uniqueness.
In 2009, the commercial deployment of the W-CDMA system is still progressing steadily not only in Europe but in North America and Asia as well, and at present, more than 180 mobile network operators have commenced 3rd Generation technologies. For example in Japan, the maximum downlink transmission data rate provided by NTT docomo in its packet services via High Speed Downlink Packet Access (HSDPA) is 7.2 Mbit/s, but the technical specifications of HSDPA and High Speed Uplink Packet Access (HSUPA) support maximum transmission data rates between a base station and mobile terminal of 14 Mbit/s in the downlink and 5.7 Mbit/s in the uplink.

Fig. Top ten mobile broadband economics (source: ITU Internet Report 2006)


Those HSPA and EVDO technologies are categorized into “3.5G” mobile broadband. Roughly speaking, at this point, Japan’s market has 100miilion subscribers, of which 90% are using 3G cell-phones , and half of them are taking benefits of 3.5G technologies. Mega-bps cell-phones are now majority there. That is the key killer application enabler in the mobile application space. The music and video clip download is quite common among younger generations, and web accesses to a wide variety of services are common practice of 70% of our general population.
What we can see beyond the HSPA technologies is 3G-LTE (Long Term Evolution) that is planned to be launched late 2010 in Japan. 3G-LTE will be required to provide short delays in addition to a dramatic leap in data rates and improved spectrum efficiency. Achieving short delays means that the time required for call setup (connection delay) and the time involved in data transfer during a call (transmission delay) will be reduced enabling the high-speed data transmission by a protocol like TCP/IP.
LTE’s downlink uses the Orthogonal Frequency Division Multiple Access (OFDMA) radio access providing high resistance to multipath interference and flexible support for a wide range of frequency bandwidths by changing the number of subcarriers. That highlights 3G LTE from the existing 3G technologies. The uplink, meanwhile, uses Single Carrier - Frequency Division Multiple Access (SC-FDMA) that can achieve low power consumption by decreasing the Peak-to-Average Power Ratio (PAPR) of cell-phones and reduce interference from other users. It is said 3G-LTE will be provided, at the beginning, to lap-top PCs as the cellular correspondent to WiMAX. Eventually, however, we will see 10~100 Mbps applications for ordinarily people with popular cell-phones in five years. The point is not the bandwidth, but the improved user experience, by the fact that the fairly improved low-latency and high-capacity mobile broadband environment will emerge soon, and it will accommodate new killer application environments in the sense of mobile Internet beyond the cellular networks.

Mobile Social Network Services in Japan
As the far east has very unique mobile ecosystems based on mobile broadband networks, VGA size display cell-phones, mobile contents (i.e., exclusive to PC users) and “smart mob” culture, SNS is also different from the other regions. Let us see its uniqueness in two SNSs: mixi and mobage-town in Japan. Those use only one language, Japanese and therefore don’t have a global reach to the rest of the world, unlike MySpace and FaceBook. Those business models are similar mainly in on-line advertisement (banner and click), and slightly different in several side businesses such as job-brokering, e-commerce, auction, and so on.
Mixi launched their business in early 2004, and has reached at having 16 million subscribes as of early 2009. A half of the age group early 20s are using this SNS, and around 15% of the nation at ages from 18 to late 50s have subscribed. The active visit rate within three days is about 52%. That is the king of SNS in Japan. Unlike MySpace, most of mixi users are using nicknames and meeting in a small group space, so as to get community entertainments, for which they write diary, read and comment each other in their daily lives. It seems that mixi provides semi-real communities that overlay real ones. Nicknames are used to keep them anonymous though, they know each other in real names within a community to which they belong.
A very interesting observation is that mixi users are becoming mobile. In late 2006, a survey on mixi access method among respondents said that it was 78.6% mainly from PC, mobile supplemental, 15.4% mainly from mobile, PC supplemental, and 6.0% solely from mobile.

Fig. mixi’s growth (source: mixi’s IR report)

The above figure summarizes the current growth of subscribers and page views. The figure shows that the number of page views from PCs is declining. On the other hand, the number of page views from mobile is getting significant. The page sizes of mobile contents is almost 1/10 of PC contents though, it seems the communication structure of mixi is changing from PC-oriented to mobile-oriented. There are several implications: 1. new subscribers are mainly from mobile users, 2. 3G mobile broadband has technically fostered the transition from PC to mobile, and 3. A way of community entertainment by its nature is required to be casual, instant, and personal.
Mobage-town is the queen of SNS in Japan. The name comes from a Japanese abbreviation of English term “mobile game town.” That has 12.3 Million subscribers and 15 billion page views per month as of late 2008. They started the SNS in 2006, and have sharply attracted teens to join them. This SNS can be conceptually summarized as an extension of Second Life in a mobile space plus their unique attractive services. The SNS has similarity with Korean game-site “Han game.” There must be nonlinear synergy effects in combination of games, SNS, content share, and e-commerce. Especially, gaming is so poplar enough to lure the teens that they have attains more than 50% penetration to Japanese teens. Interestingly, mobage-town only allows cell-phones to access. That is mobile-only SNS and requires their subscribers to use high-end cell-phones equipped with adobe flash players, since all the contents are provided in the flash format, and thus (on-line) gaming has become possible for millions of cell-phone users. We can summarize the technical enablers. Those are always-on-anywhere, flat rate pricing broadband networks, VGA-size display, graphic processors tolerant to manipulate adobe flash contents. Without those enablers, mobage-town has not emerged.

Recent five years, the term “convergence” has been a buzz word in communication industries. Especially, the convergence between fixed and mobile networks is getting attracted in a wide range of mobile services that utilize fixed communications infrastructure to complement the mobile service. That convergence remains just at network economics in providing less-redundant functionality and less-payment. What we see here, on the other hand, is mobile unique evolution of multimedia applications, where application-layer convergence has occurred as “mainly mobile, complementary PC.” As mobile broadband technologies evolve, a higher layer convergence will be essential. Mixi shows a good example, which is not from the single invention.

3/22/2009

Bridging the two spaces (prep. for ICASSP 2009)

I was invited by Berna Erol to a panel discussion at ICASSP 2009 which will be held in Taipei, Taiwan in April 19th-24th 2009. (further information at: http://icassp09.com/)
My main topic will be related to “bridging the real space and the information space” as depicted in the picture below.





The point is clear and crisp where many mobile phones are now being equipped with various I/O devices and sensors, such as accelerometers, GPS, microphones, and cameras. These allow applications to be context-aware and enable easy integration of user's real environment wit applications. Mobile device's peripheral and sensor enhancement will be an extremely fertile incubation environment for new and innovative killer applications in our daily life. That definitely differentiates mobile Internet from fixed-line Internet of PCs. That is already happening in far-east countries, where mobile devices are evolving not as miniaturized mobile PCs but as devices with unprecedented capabilities.
2D barcode, called QR code, and its related applications are good instances in discussing the difference. A QR Code is a 2D matrix code created by Japanese corporation Denso-Wave in 1994. Let’s see one video shot which I shot two weeks ago.






Now you saw how the real object (i.e., a magazine page) is connected to the related portal site through the phone. The usage of the 2D barcode is not limited to magazines or published documents. Such a code can be attached with any real objects as far as those have a printable room. Here is another good example:when I was walking around Ginza (corresponding to the fifth street in N.Y.) in Tokyo. I found a big 2D bar code which introduced a company’s home page.
That was readable with my cell-phone!

Apart form the barcode approaches, connecting real objects with the internet by capturing a natural scene is on the way. Evolution Robotics, a US-based company, commercialized a visual search engine called “ER Search” on a line of camera phones. Here is another video which I shot two weeks ago.







That technology can search only a set of registered image patterns like CD jackets, magazine cover pages, etc. For my wine labels, the engine couldn’t retrieve my favorite California wine descriptions, although the technology was developed in California!

Now, we have a technical progress in bridging the two worlds: real and virtual on one hand. On the other hand, we are confront with a big technical challenge, which is authentication of visual tags such as the 2D barcodes or the registered images. You can imagine that malicious QR codes can be pasted over original QR codes. Those phony codes can lead phone users to wrong malicious sites. Phishing with phony QR codes now is going to be a big threat to our mobile society. The world is not simple.