Benefits form ubiquitous network

Our Door
1. Use seamless telecommunication services without being aware of differences in networks such as mobile phone network and WiFi network
2. Access office and home network form outside
3. Take care of elder person or disabled person by using ICT

Office
1. Efficient information sharing
2.Energy saving in an office
3.Rapid configuration of information system to meet the change of business environment

National Infrastructure
1. Gather and provide traffic and weather information to protect accident and disaster.
2. Observe condition of structure of bridge, high way and buildings
3. Observe earthquake, typhoon, volcano etc
4. Provide public services on the e-government

Home
1. Energy saving and provide comfortable environment
2. Distant learning, telemedicine.
3. Control every appliance from outside
4. Observe outside to prevent fire and criminals

参考：Mobile Phone based on Ad Hoc network Using Built in bluetooth for ubiquitous life

TDD, FDD => TD-SCDMA

Basically most of the UMTS networks in operation are Frequency Division Duplex (FDD) based. There is also another variant called the Time Division Duplex or TDD.

Notice, we have two kinds of TDD.
One is WTDD (Wideband TDD) that uses normal 5MHz bandwidth. There is also another name for WTDD is High Chip Rate TDD (HCR-TDD).

The other is NTDD (Narrowband TDD). NTDD has another name as Low Chip Rate TDD(LCR-TDD). This is call as TD-SCDMA or Time division synchronous CDMA.

"Synchronous" implies that uplink signals are synchronized at the base station receiver, achieved by continuous timing adjustments. This reduces the interference between users of the same timeslot using different codes by improving the orthogonality between the codes, therefore increasing system capacity, at the cost of some hardware complexity in achieving uplink synchronization.

The normal bandwidth of FDD or TDD mode of operation is 5 MHz. This gives a chip rate of 3.84 Mcps (Mega chips per second). The corresponding figure for TD-SCDMA is 1.66 Mhz and 1.28 Mcps.

参考：3G and 4G Wireless Blog

Challenges in Mobile phone Ad hoc Networks

Dr. Ariela Zeira, InterDigital's Vice-President of Advanced Air Interfaces shows the possible problems in having an LTE based approach for a Mobile phone 'Ad-Hoc' network

1. Grouping of helper nodes
2. Power Control mechanisms
3. Base station coordination
4. Frame Structures
5. HARQ Mechanisms
6. Crosslink Synchronization
7. Discovery of Neighbor terminals
8. Power management
9. Control signaling to enable crosslink communication
10. Scheduling and resource mangement
11 Relaying protocols

Set a variable value in MAC layer.

adding a variable in

in mac-802_11.h

class MAC_MIB {
private: u_int32_t ChannelThreshold;

public: inline u_int32_t getChannelThreshold() { return(ChannelThreshold);}

}

in mac-802_11.cc

00172 MAC_MIB::MAC_MIB(Mac802_11 *parent)
00173 {
00174     /*
00175      * Bind the phy mib objects.  Note that these will be bound
00176      * to Mac/802_11 variables
00177      */
00178    
00179     parent->bind("ChannelThreshold_", &ChannelThreshold);
00182 }

use the variable

thresh = macmib_.getChannelThreshold();


In the tcl file
Mac/802_11 set ChannelThreshold_ 1

The chinese are becoming more and more mobile savvy

In a news release Friday, China Internet Network Information Center (CNNIC) announced that China's mobile phone Internet users reached 233 million in December 2009, a growth of 120 million users from 2008. Among these users, 30.7 million accessed the Internet exclusively on their mobile phones.

China's online population reached 384 million as of December 2009, growing 28.9 percent from figures recorded in 2008, said CNNIC in the report.

PHPでUserAgentから携帯かどうか判定

$ua = $_SERVER['HTTP_USER_AGENT'];

if (preg_match("/^DoCoMo\/2\.0/i", $ua)) { // DoCoMo FOMA (XHTML)

$isMobile = true;

} else if (preg_match("/^DoCoMo\/1\.0/i", $ua)) { // DoCoMo MOVA

$isMobile = true;

} else if (preg_match("/^SoftBank/i", $ua)) { // SoftBank

$isMobile = true;

} else if (preg_match("/^(Vodafone|MOT-)/i", $ua)) { // Vodafone 3G

$isMobile = true;

} else if (preg_match("/^J\-PHONE/i", $ua)) { // Vodafone 1G,2G

$isMobile = true;

} else if (preg_match("/iPhone/i", $ua)) { // iPhone

$isMobile = true;

} else if (preg_match("/^KDDI\-/i", $ua)) { // au (XHTML)

$isMobile = true;

} else if (preg_match("/UP\.Browser/i", $ua)) { // au (HDML) TU-KA

$isMobile = true;

} else if (preg_match("/WILLCOM/i", $ua) ||

preg_match("/DDIPOCKET/i", $ua)){ // WILLCOM Air EDGE

$isMobile = true;

} else if (preg_match("/^PDXGW/i", $ua)) { // WILLCOM EDGE LINK

$isMobile = true;

} else if (preg_match("/^(L\-mode)/i", $ua)) { // L-mode

$isMobile = true;

} else {

$isMobile = false;

}