The issue of WiFi network in Bangladesh prospective.

If we want to make digital our country we need Wifi network.One day public WiFi is everywhere we go, such as at coffee shops, airport, rail station, park, libraries, print shops and even some fast food restaurants.We have already WiFi in some university like university of Dhaka. We can easily connect our laptop to it and we will be surfing the web in no time at all. Although it is convenient, it may not be safe. Hackers and scammers can tap into our unsecured connections and easily steal your personal information. We can protect your computer if you take a couple of precautions.

Help from:http://www.wisegeek.com/is-public-wifi-safe.htm

When we are using public WiFi, we have to sure to use a firewall. Firewalls give us extra protection, though not foolproof, from people trying to scam your information. Windows XP and Vista operating systems have built in firewalls.We can set up a firewall on computer by visiting some website as Microsoft website.

Public WiFi locations are not the place to conduct business that involves the use of private information. If a scammer hacks into a computer, all of us -- or our friend's -- personal information will be obtained. Even if we have a firewall, there is no guarantee that our information won't be stolen. Save business-related work, valuable data by using private network.

It may seem like a public WiFi location is the perfect place to do a little online shopping. It is, in fact, the worst place. While online shopping, we are likely to use our credit card to pay for our purchases. This places our credit card information out in cyberspace for dishonest people to use.

The suggestion is Feel free to browse your favorite online stores, but save the actual purchase until you have a secure connection.Never balance your checking account, or use any other online banking service, when accessing the Internet at a public WiFi location. Besides the stranger that may be looking over your shoulder, there are other people that may be tapping into your network connection. They can acquire your username and password as well as all your personal information.

We have to sure when using public WiFi that we disconnect any networked computers and file sharing. If a hacker does manage to access this computer, they will also be able to access any computers linked to that network. All the information stored on the computers will be accessible.

We should be aware of using digital network that doesn't mean I do not like WiFi network or I am opposing "Digital Bangladesh". I want to say our student should use it or the person have less valuable data to loss he should use it and important data must be used by taking above precaution.
source:http://www.wisegeek.com/

WiFi network may be best communication in a campus.

A Wi-Fi® or WiFi network is the most popular type of wireless network used to connect computers and share online access at home or at the office now-a-dys. It broadcasts network traffic over radio waves so does not require cable. It does this using a central device that is often three components in one: a network hub, router, and high-speed Internet modem. For simplicity we'll refer to this device as a router, though in some cases the router, which has a built-in hub, is purchased separately from the modem.

Each machine on a WiFi network must have an installed WiFi card or an external WiFi adapter. These devices incorporate a receiver and transmitter to send and receive data over the network to the router. Broadcast range varies up to 300 feet (~100m) or more, but is fairly centralized, creating what is termed a local area network (LAN). The WiFi router, cards and adapters use a common language or protocol to communicate that is compliant with a standard known as IEEE 802.11.

Within the 802.11 standard there are different generations of protocols, each designated by an additional letter. Generations to date include 802.11a, 802.11b, 802.11g and 802.11n. The first two flavors are now legacy, but as of spring 2009, 802.11g is still in widespread use with the newer and faster 802.11n on the road to replacing it.

All WiFi components in the network must support the same flavor or generation of 802.11 standards to communicate. If the router only supports 802.11g, the WiFi cards and adapters must also support 802.11g. If the router supports 802.11n, the cards and adapters must also support 802.11n.

Some routers, cards and adapters manufactured during transitional periods between changing standards will be designed to support both the current and the new protocol for maximum flexibility. These devices will be more expensive since the “g” and “n” networks utilize different frequency bands, requiring two radios instead of just one.

Components made for a WiFi network might be certified by the Wi-Fi Alliance. Certification ensures the product is fully compliant with the standard(s) it supports. Only a wireless network that has certified components is a true Wi-Fi network by technical standards, as Wi-Fi is a trademark of the Wi-Fi Alliance. However, “WiFi” or “wifi” has been generalized to mean any wireless network that complies with 802.11 whether components are officially certified or simply marketed as compatible.

When setting up a WiFi network it’s best to use the newest technology available in order to future-proof the investment. For home use, non-certified WiFi components might save a little money and will more than likely do the job just fine. If setting up a wireless network for a business, a true Wi-Fi network with certified components that have been fully tested and are known to be fully compliant might be a more prudent choice.

The 802.11 standards used in a WiFi network differentiate it from other types of wireless communications that use radio waves, such as Bluetooth® networks. Bluetooth uses a weaker, less robust radio band that travels a much shorter distance of up to about 30 feet (~10m). Bluetooth is primarily designed to connect battery-operated personal devices to one another for interoperability, creating a personal area network (PAN). Bluetooth might be used to pass files from a cell phone to a computer, to synchronize a personal digital assistant with a laptop, or to connect a wireless headset with a cell phone or MP3 player.

source: http://www.wisegeek.com/what-is-a-wifi-network.htm

Bluetooth is popular technology to all.

Bluetooth is the name of a new technology that is now becoming commercially available. It promises to change significantly the way we use machines.A short-range radio technology aimed at simplifying communications among Internet devices and between devices and the Internet. It also aims to simplify data synchronization between Internet devices and other computers.
Bluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. The key features of Bluetooth technology are robustness, low power, and low cost. The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other.
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short length radio waves) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Invented by telecoms vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization. Today Bluetooth is managed by the Bluetooth Special Interest Group.

Range

Bluetooh is based on short radio transmissions and the regular range for the Bluetooth radius is 10 metres. Upgrade your equipment, however, and you can extend that tenfold into 100 metres, which is great for such a portable technology.

Bandwidth

You can do more with your Bluetooth. The maximum data transfer rate (that is, how much information can be transmitted at once) is 724 kbits/s for a maximum of three voice channels (plus data.)

Security Measures

Not one but two different security mechanisms have been implemented to ensure a high level of security:

• Authentication - This prevents access to critical data and makes it impossible to falsify the origin of any message.
• Encryption - This prevents anyone from eavesdropping on you and maintain the privacy of the link.

Is CDMA best alternative of GSM?

CDMA:
Code division multiple access (CDMA) is a channel access method utilized by various radio communication technologies. CDMA is a "spread spectrum" technology, allowing many users to occupy the same time and frequency allocations in a given band/space. CDMA (Code Division Multiple Access) assigns unique codes to each communication to differentiate it from others in the same spectrum. In a world of finite spectrum resources, CDMA enables many more people to share the airwaves at the same time than do alternative technologies.

The CDMA air interface is used in both 2G and 3G networks. 2G CDMA standards are branded cdmaOne™ and include IS-95A and IS-95B. CDMA is the foundation for 3G services: the two dominant IMT-2000 standards, CDMA2000® and WCDMA, are based on CDMA.

CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access(TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency. CDMA is a form of spread-spectrum signaling, since the modulated coded signal has a much higher data bandwidth than the data being communicated.
An analogy to the problem of multiple access is a room (channel) in which people wish to communicate with each other. To avoid confusion, people could take turns speaking (time division), speak at different pitches (frequency division), or speak in different languages (code division). CDMA is analogous to the last example where people speaking the same language can understand each other, but not other people. Similarly, in radio CDMA, each group of users is given a shared code. Many codes occupy the same channel, but only users associated with a particular code can understand each other.
Multiplexing
One of the basic concepts in data communication is the idea of allowing several transmitters to send information simultaneously over a single communication channel. This allows several users to share a bandwidth of different frequencies. This concept is called multiplexing.

Why CDMA used for:

1. One of the early applications for code division multiplexing is in GPS. This predates and is distinct from cdmaOne.
2. The Qualcomm standard IS-95, marketed as cdmaOne.
3. The Qualcomm standard IS-2000, known as CDMA2000. This standard is used by several mobile phone companies, including the Globalstar satellite phone network.
4. CDMA has been used in the OmniTRACS satellite system for transportation logistics.

Data Transfer Speed:
 With the advent of cellular phones doing double and triple duty as streaming video devices, podcast receivers and email devices, speed is important to those who use the phone for more than making calls. CDMA has been traditionally faster than GSM, though both technologies continue to rapidly leapfrog along this path. Both boast "3G" standards, or 3rd generation technologies.



Subscriber Identity Module (SIM) cards:

 In the United States only GSM phones use SIM cards. The removable SIM card allows phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself is tied to the network, rather than the actual phone. Phones that are card-enabled can be used with any GSM carrier.

The CDMA equivalent, a R-UIM card, is only available in parts of Asia but remains on the horizon for the U.S. market. CDMA carriers in the U.S. require proprietary handsets that are linked to one carrier only and are not card-enabled. To upgrade a CDMA phone, the carrier must deactivate the old phone then activate the new one. The old phone becomes useless.

Roaming: 

For the most part, both networks have fairly concentrated coverage in major cities and along major highways. GSM carriers, however, have roaming contracts with other GSM carriers, allowing wider coverage of more rural areas, generally speaking, often without roaming charges to the customer. CDMA networks may not cover rural areas as well as GSM carriers, and though they may contract with GSM cells for roaming in more rural areas, the charge to the customer will generally be significantly higher.

International Roaming:

 If someone need to make calls to other countries, a GSM carrier can offer international roaming, as GSM networks dominate the world market. If he travel to other countries he can even use your GSM cell phone abroad, providing it is a quad-band phone (850/900/1800/1900 MHz). By purchasing a SIM card with minutes and a local number in the country you are visiting, you can make calls against the card to save yourself international roaming charges from your carrier back home. CDMA phones that are not card-enabled do not have this capability, however there are several countries that use CDMA networks. Check with your CDMA provider for your specific requirements.
According CDG.org, CDMA networks support over 270 million subscribers worldwide, while GSM.org tallies up their score at over 1 billion. As CDMA phones become R-UIM enabled and roaming contracts between networks improve, integration of the standards might eventually make differences all but transparent to the consumer.
The chief GSM carriers in the United States are Cingular Wireless, recently merged with AT&T Wireless, and T-Mobile USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin Mobile. There are also several smaller cellular companies on both networks.

GSM, the ew invention of human being

What is GSM?

GSM (Global System for Mobile communications) is an open, digital cellular technology used for transmitting mobile voice and data services.
GSM is the most popular standard for mobile telephony systems in the world. The GSM Association, its promoting industry trade organization of mobile phone carriers and manufacturers, estimates that 80% of the global mobile market uses the standard. GSM is used by over 3 billion people across more than 212 countries and territories. Its ubiquity enables international roamingarrangements between mobile phone operators, providing subscribers the use of their phones in many parts of the world. GSM differs from its predecessor technologies in that both signaling and speech channels are digital, and thus GSM is considered a second generation (2G) mobile phone system. This also facilitates the wide-spread implementation of data communication applications into the system.

What does GSM offer?

GSM supports voice calls and data transfer speeds of up to 9.6 kbit/s, together with the transmission of SMS (Short Message Service).

GSM operates in the 900MHz and 1.8GHz bands in Europe and the 1.9GHz and 850MHz bands in the US. The 850MHz band is also used for GSM and 3G in Australia, Canada and many South American countries. By having harmonised spectrum across most of the globe, GSM’s international roaming capability allows users to access the same services when travelling abroad as at home. This gives consumers seamless and same number connectivity in more than 218 countries.

Terrestrial GSM networks now cover more than 80% of the world’s population. GSM satellite roaming has also extended service access to areas where terrestrial coverage is not available.



GSM carrier frequencies

GSM networks operate in a number of different carrier frequency ranges (separated into GSM frequency ranges for 2G and UMTS frequency bands for 3G), with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands. Where these bands were already allocated, the 850 MHz and 1900 MHz bands were used instead (for example in Canada and the United States). In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems.
Most 3G GSM EDGE networks in Europe operate in the 2100 MHz frequency band.
Regardless of the frequency selected by an operator, it is divided into timeslots for individual phones to use. This allows eight full-rate or sixteen half-rate speech channels per radio frequency. These eight radio timeslots (or eight burst periods) are grouped into a TDMA frame. Half rate channels use alternate frames in the same timeslot. The channel data rate for all 8 channels is 270.833 kbit/s, and the frame duration is 4.615 ms.
The transmission power in the handset is limited to a maximum of 2 watts in GSM850/900 and 1 watt in GSM1800/1900.

Phone locking

Sometimes mobile phone operators restrict handsets that they sell for use with their own network. This is called locking and is implemented by a software feature of the phone. Because the purchase price of the mobile phone to the consumer is typically subsidised with revenue from subscriptions, operators must recoup this investment before a subscriber terminates service. A subscriber may usually contact the provider to remove the lock for a fee, utilize private services to remove the lock, or make use of free or fee-based software and websites to unlock the handset themselves.
In some territories (e.g., Bangladesh, Hong Kong, Pakistan, India) all phones are sold unlocked. In others (e.g., Belgium, Finland) it is unlawful for operators to offer any form of subsidy on a phone's price.

GSM service security

GSM was designed with a moderate level of service security. The system was designed to authenticate the subscriber using a pre-shared key and challenge-response. Communications between the subscriber and the base station can be encrypted. The development of UMTS introduces an optional Universal Subscriber Identity Module (USIM), that uses a longer authentication key to give greater security, as well as mutually authenticating the network and the user - whereas GSM only authenticates the user to the network (and not vice versa). The security model therefore offers confidentiality and authentication, but limited authorization capabilities, and no non-repudiation.
GSM uses several cryptographic algorithms for security. The A5/1 and A5/2 stream ciphers are used for ensuring over-the-air voice privacy. A5/1 was developed first and is a stronger algorithm used within Europe and the United States; A5/2 is weaker and used in other countries. Serious weaknesses have been found in both algorithms: it is possible to break A5/2 in real-time with a ciphertext-only attack, and in February 2008, Pico Computing, Inc revealed its ability and plans to commercialize FPGAs that allow A5/1 to be broken with a rainbow table attack. The system supports multiple algorithms so operators may replace that cipher with a stronger one.
On 28 December 2009 German computer engineer Karsten Nohl announced that he had cracked the A5/1 cipher. According to Nohl, he developed a number of rainbow tables (static values which reduce the time needed to carry out an attack) and have found new sources for known plaintext attacks. He also said that it is possible to build "a full GSM interceptor ... from open source components" but that they had not done so because of legal concerns.
In 2010, threatpost.com reported that "A group of cryptographers has developed a new attack that has broken Kasumi, the encryption algorithm used to secure traffic on 3G GSM wireless networks. The technique enables them to recover a full key by using a tactic known as a related-key attack, but experts say it is not the end of the world for Kasumi." Kasumi is the name for the A5/3 algorithm, used to secure most 3G GSM EDGE traffic.
Although security issues remain for GSM newer standards and algorithms may address this. New attacks are growing in the wild which take advantage of poor security implementations, architecture and development for smart phone applications. Some wiretapping and eavesdropping techniques hijack the audio input and output providing an opportunity for a 3rd party to listen in to the conversation. Although this threat is mitigated by the fact the attack has to come in the form of a Trojan, malware or a virus and might be detected by security software.

EDGE

Enhanced Data rates for GSM Evolution (EDGE) (also known as Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC), or Enhanced Data rates for Global Evolution) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE is considered a 3G radio technology and is part of ITU's 3G definition. EDGE was deployed on GSM networks beginning in 2003— initially by Cingular (now AT&T) in the United States.
EDGE is standardized by 3GPP as part of the GSM family, and it is an upgrade that provides more than three-fold increase in both the capacity and performance of GSM/GPRS networks. It does this by introducing sophisticated methods of coding and transmitting data, delivering higher bit-rates per radio channel.
EDGE can be used for any packet switched application, such as an Internet connection. EDGE-delivered data services create a broadband internet-like experience for the mobile phone user. High bandwidth data applications such as video services and other multimedia benefit from EGPRS' increased data capacity.
Evolved EDGE continues in Release 7 of the 3GPP standard providing reduced latency and more than doubled performance e.g. to complement High-Speed Packet Access (HSPA). Peak bit-rates of up to 1Mbit/s and typical bit-rates of 400kbit/s can be expected.

Whice one is best? WiMAX or LTE

WiMAX (worldwide interoperability for microwave access) is a fourth-generation (4G) telecommunications technology primarily for fast broadband.

Also a 4G mobile technology, LTE allows a peak download speed of 100 megabits per second (Mbps) on mobile phones, compared with 20Mbps for 3G and 40Mbps for WiMAX.

Biese reckons LTE is the next step for mobile networks like GSM, WCDMA/HSPA and CDMA in the move to future networks and services.

The common belief is that the natural migration path is from 2G to GPRS, from GPRS to 3G, and from 3G to LTE. But IDC Asia/Pacific’s telecom research director Bill Rojas has a differing view. To him, LTE is a totally new set-up.

It has been reported that LTE’s main advantage over WiMAX, in addition to speed, is that it is part of the popular GSM technology and can allow backward compatibility with both 2G and 3G networks.

However, LTE is fast catching up with WiMAX even though the WiMAX Forum, an industry organisation, stresses that its platform is at least two years ahead in terms of equipment availability and testing.

The Global Suppliers Association (GSA) says there are more than 59 LTE network commitments in 28 countries. In comparison, according to the WiMAX Forum, there are 559 WiMAX networks worldwide.

Do you know Electric car buyers to get £5,000 grant?

Drivers could receive up to £5,000 to subsidise the purchase of an electric car under a new £250 million Government scheme designed to promote environmentally-friendly transport.
The plans, due to come into force in 2011 for five years, are also aimed at boosting the green technology sector as Britain comes out of recession.


But opposition politicians, car groups and environmental groups dismissed the proposals as a gimmick, warning that electric cars would be expensive and impractical without a much more developed support system, including a national recharging network.
Transport and environmental groups welcomed the move but insisted the Government would need to work very hard on the details of such a plan.


The government remained silent on a separate plan being pushed by industry lobbyists to pay consumers £2,000 to scrap old cars and buy new models. The proposal, put forward by the business department, is the subject of Treasury concerns about its cost. An announcement is expected next week in the Budget.