Bluetooth Players

Bluetooth Chip Manufacturers Bluetooth chips are being manufactured by the likes of VLSI, owned since June 2nd1999 by Philips. In October 1999, Motorola acquired Digianswer, an early Bluetooth adopter, to boost its Bluetooth and HomeRF portfolio. VLSI has supplied Bluetooth chips to Ericsson for its wirefree Headset reviewed below Lucent Technologies Microelectronics Group (see below), Cambridge Silicon Radio (CSR) and others also manufacture Bluetooth chip solutions.

Ericsson Bluetooth Headset Ericsson has unveiled the Bluetooth Headset (available on the market in mid 2000), a headset that connects to a mobile phone by a radio link instead of a cable. It is the first ever handsfree accessory to incorporate Bluetooth technology, the future industry standard for wireless communication between devices. The Ericsson Bluetooth Headset is a lightweight, wireless mobile phone headset, with a built-in Bluetooth radio chip that acts as a connector between the headset and the Bluetooth plug on the Ericsson phone. Weighing 20 grams (0.75 oz.), the Bluetooth Headset sits comfortably on either ear and can be used with Ericsson T28, T28 WORLD and R320 cellular phones.

Lucent Technologies Lucent Technologies Microelectronics Group has announced its first integrated Bluetooth chipset solution, designed to enable wireless information sharing between personal communications devices and speed end products to market through simplified development and certification. Lucent's new solution consists of a single-chip radio subsystem and a baseband controller, complete with protocol software. The W7400 is available with a Lucent-supplied software protocol stack. Samples and development tools for the W7400 will be available in March 2000, with production starting in 3Q 2000. Interference Issue Possible interference between different wireless data standards that do not require federal licensing agreements could delay Bluetooth products from coming to market. According to Cahners Business Information, the 2.4-GHz radio frequency broadcast on an Industrial and Scientific Network, or ISN, already carries traffic from various industrial communication devices and Bluetooth signals could interfere with ISN traffic. There are also concerns about use of Bluetooth on airplanes. While cell phones and pagers are usually turned off in flight, Bluetooth has been designed to maintain uninterrupted connections even while in motion, while the devices are still in their carrying cases, or even if the devices aren't turned on.

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What is Bluetooth?

Bluetooth is an alliance between mobile communications and mobile computing companies to develop a short-range communications standard allowing wireless data communications at ranges of about 10 meters.

Bluetooth will encompass both a standard communications interface and a low-cost computer chip. It is a cross between the DECT (Digital European Cordless Telephone) and iRDA (infra Red Data Association) technologies. Bluetooth was conceived by Ericsson, but founded by Nokia, Ericsson, IBM, Intel and Toshiba. The Bluetooth Interest Group has since been joined by hundreds of companies including One2One; a UK mobile network operator, Motorola, Qualcomm, Compaq, Dell, 3Com Palm, VLSI, Xircom, Psion Dacom and Lucent. Bluetooth does NOT involve mobile network transactions- its spectrum is freely available to use in the unlicensed spectrum area (at 2.45 gigahertz). Data transmission speeds using Bluetooth are expected to be between 720 kbps and one megabit per second (Mbps).

Bluetooth will facilitate wireless Local Area Networks in which networks of different handheld computing terminals and mobile terminals can communicate and exchange data, even on the move and when there is no line-of-sight between those terminals. Bluetooth will mean that if users have several (Bluetooth-enabled) portable terminals, they can nonetheless use them with all the advantages of an integrated smart phone, without having to re-enter data or find the most recent versions on different terminals. This kind of synchronization and exchange of data are Bluetooth’s major applications, as are electronic commerce applications such as electronically paying for parking meters, bus tickets, shopping, movies and so on. Smart offices are envisaged in which an employee with a Bluetooth device is automatically checked in when entering the building and this triggers a series of actions such as lights and PCs being switched on. The Bluetooth partners see one of its main advantages as being that it does not need to be set up- Bluetooth runs in the background and line of sight is not even needed for the machines to automatically initiate and trigger processes. Such proactive intelligence could turn out to be a nuisance rather than a convenience for Bluetooth users unless it is under the control of the device owner(s). Indeed, the Bluetooth standard does incorporate these kinds of control mechanisms, since each device is assigned a unique 12 byte address and to connect to that device, its address must be known. There will also be an enquiry feature so to search for other Bluetooth-enabled devices within range. The Bluetooth specification was outlined in early 1999, with Bluetooth-enabled mobile terminals such as laptops, smart phones, handheld computers and so on likely to be first available by the industry conference "Telecom 99" in Geneva, Switzerland. Commercial Bluetooth terminals are expected to be available in the year 2000. In one negative prediction for Bluetooth, the September 1998 issue of "Wired" magazine listed Bluetooth at position one in its "Hype List" which aims at "Deflating this month’s overblown memes". It commented that "This wireless LAN technology overcomes infrared’s line-of-sight limitations, but Bluetooth’s true application, much less its market potential, won’t emerge until there’s a critical mass of RF-chip PCs, handhelds, and phones. And even then, people looking to move data between gadgets might find it hard to sever their emotional connection to the entrenched wireline option." Bluetooth was given a life expectancy of 24 months. Whilst it is true to say that other similar ideas to network electronic terminals and household appliances have come and gone in the past, such as Novel NetWare, Bluetooth does have the backing of a lot of market leading mobile phone and modem manufacturers. Others have failed because they have not been able to achieve a critical mass of wired appliances when licensing their technology. See http://www.bluetooth.com

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The battle for 4G advantage

The race to the next of mobile standards is gathering pace in Japan. "If you ask DoCoMo, they will tell you they have a 4G lab," says Bengt Nordstrom, chief strategy officer at inCode. But research is still in the very early stages.

Specification work for 3G LTE(long-term evolution) - also known as Super 3G- is under way, says Nordstrom. That will deliver a new core network architecture and air interface. "[Japanese operators] are investing heavily in that," DoCoMo in particular.

"DoCoMo is currently at the stage of testing the components and technologies that will constitute the 4G system," says spokesperson Miki Nakajima McCants. "DoCoMo is playing a leading role in research on the proposed 4G access system, but we are not yet at the developmet stage, nor are we collaborating with other operators."

Japan is making sure it is at the forefront of development of LTE and 4G, says Gavin Patterson, analyst at Informa. He points out that historically Asian vendors suffered from Japan's decision to adopt the proprietary PDC standard for 2G mobile services.

"[There's] only going to be one 4G standard," says Patterson, which means one key concern will be marrying legacy GSM with legacy CDMA.

"4G is considered by the industry to be the enhancement of radio network bandwidth," syas Hideo Okinaka, VP technical standars, at KDDI. "We do not ignore the importance of 4G in this definition, but we do not think a single radio interface meets any of [the] market requirements in the future."

KDDI is focusing on the Ultra3G initiative it announced in June 2005. Central to this is a transport core network based on IP version 6 and an IMS/MMD-based service control platform. KDDI is working to introduce Revision A by the end of this year.

"Initially we will use EV-Do Rev.A as a means to enhance reverse link bandwidth and capacity (154 kilobits per second to 1.3 Mbps)," says KKDI's Okinaka.

"The battle in Japan between KDDI and DoCoMo is already along technical lines," says Informa's Patterson.

If KDDI does not offer Revision A, subscribers might migrate to DoCoMo, and vice versa. There's not much they can do except "keep upgrading their network systems," says Patterson.

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What is 4G?

In a Cutt Newsletter (2004) issue it is mentioned that while current 3G services are working to enable transactional wireless communications like location-based services, wireless shopping, personal services, email and multimedia data transfer, these are at much lower speeds compared to the 100 MBPS to 1 GBPS of 4G. As demand builds for high-quality, streaming video and audio, only 4G systems will be able to accommodate growing consumer and business expectations. Japan, China and South Korea plan to work together with developing new technologies like fourth-generation mobile phones says Japanese local papers. Ongoing talks have been underway for the last several months to discuss how to work together in the best possible way including

those for the 2008 Beijing Olympics and future Internet systems, said an official at the telecommunications ministry. A 4G orientated meeting was held in Seoul in March with officials from the above countries, where they agreed to share information and work together on developing 4G mobile phones. In Eliza Evans and others (2004) the implications of 4G network are discussed in detail. They predict that if implemented, the projected 4G technology may facilitate a true IP cellular network. 4G mobile phone technology supports Internet Protocol version 6 (IPv6) and promises faster communication speeds (100 megabits per second), capacity and diverse usage formats. These formats would provide richer content and support for other public networks such as optical fibre and wireless local area networks. 4G is currently only an ideal. Still, some companies are incorporating new technological advances into cellular technology, something that some companies are calling “3.5G.” 3.5G technology, the convergence of cellular and wireless LAN technologies, has led to a handset that makes calls using Voice over Internet Protocol (VoIP) when a 802.11 network is available (for example, when at home or at the office), then switches to a 3G cellular network when mobile.  Someday 4G networks may replace all existing 2.5G and 3G networks, perhaps even before a full deployment of 3G. Multiple 3G standards are springing up that would make it difficult for 3G devices to be truly global. A strong need exists to combine both the wireless (LAN) concept and cell or base station wide area network design. 4G is seen as the solution that will bridge that gap and thereby provide a much more robust network. Table 2, lists down the comparison between 3G and the upcoming 4G networks.

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Wi-Fi Security tips for Home networks

Hopefully we've scared you into resolving to do something about security on your wireless network (and on the wired one too!). To make the process as painless as possible, we've created a list of steps to follow. No network is completely secure, but after you've implemented the recommendations here, wireless hackers will likely choose an easier target. These steps apply to both home and small office networks that have a standard wireless router, and possibly one or more roaming access points.

Top 10 Security Tips for Home Wi-Fi Networks Change your router's access name and password. Don't let users piggyback onto your Wi-Fi net -- turn off peer-to-peer connections. Stop broadcasting your router's network ID. Approve all wireless network users in advance. Turn on wireless data encryption. Periodically check router logs for rogue users. Use a strong firewall. Password-protect your computers and files. Put your wireless network on its own subnet. Turn off wireless cards and routers when not in use.  1. Change your router's name and password. This is always the first line of defense. It's easy for attackers to find out what the default name and password are for various manufacturers. Many also default to using the standard 192.168.1 or 2 subnet internally and give the router itself the IP address of 192.168.1.1 or 192.16.2.1. You should make sure you rename the router, assign a strong password for accessing the router configuration software, and consider changing the IP addressing to a different internal subnet like 192.168.12 or 192.168.83 (you can use any number from 1 to 254 in most cases). 2. Enable infrastructure mode only on all access points and clients on the network. Disable the "ad-hoc" mode, which lets clients set up peer-to-peer networks and could allow rogue users to connect to your network through a legitimate wireless client. 3. Disable SSID broadcast. The SSID (Service Set Identifier) is essentially the network name for the wireless portion. A wireless access point (AP) or router in open network mode will periodically broadcast a beacon signal (usually about 10 times each second) which announces to the world that the network is live and ready to go. The beacon also includes data such as the signal strength and functional capabilities of the AP as well as the SSID. With broadcasting off, wireless clients must first know the SSID before they can connect. For home networks, this broadcast information is not necessary. You can simply type in the SSID in your wireless client's setup dialog once, and it will be remembered in future connections. Experienced hackers can still find such "closed" networks, but at least you will not be openly inviting them. In public-access hotspots or large company Wi-Fi nets, it may be still be necessary to broadcast the SSID so that as wireless clients enter the network they are automatically notified of what the SSID is so they can try to establish a connection. There are other precautions to take in these cases, as we'll see later on. 4. Turn on the MAC addressing filter in your wireless router. Most Wi-Fi gateways let you restrict access to known MAC (Media Access Control) addresses. Each network device (such as a computer, Wi-Fi card, or printer) has a unique MAC address, and by allowing access only to pre-defined MAC addresses you greatly reduce the risk of rogue clients connecting with or perusing your network resources. This takes the closed network concept a step further. Sound foolproof? Not quite. Even if your SSID isn't broadcast and you restrict access to known MAC addresses, your wireless network may still be detected and compromised. Hackers can capture the wireless data packets as they travel from your access point to your wireless client or vice versa. The captured packets may reveal both the SSID and the MAC addresses of client devices communicating with the network. Once a MAC address is known a malicious user can "spoof" the MAC address of the attacking system to make a computer look like it's one of the accepted systems and allow it to connect. So you should still take additional precautions. 5. Enable WEP (Wired Equivalent Privacy) or WPA (Wi-Fi Protected Access) encryption. Encryption is the next step in the wireless security ladder. WEP is the original Wi-Fi encryption scheme, and comes in several flavors -- 40-, 64-, and 128-bit. However, its underlying algorithm is flawed and subject to relatively easy cracking. Without going into the gory technical details, if you want to test your WEP connection to see how easy it is to capture packets and decode the key, you can use a tool like AirSnort. The longer 128-bit encryption keys require transmitting more data, but don't offer significantly better protection than 40- or 64-bit encryption, and significantly reduce performance. Taking all of that into consideration, WEP is still better than nothing. The lock on your front door is also fairly easy for a professional thief to pick but it doesn't stop you from turning the key when you leave the house. Even flawed security will keep out opportunistic hackers (the kind who look for cars with keys in the ignition), so it's worth adding that extra layer of protection. After the weaknesses of WEP were uncovered wireless equipment manufacturers rushed to create WPA, which improves upon WEP while also being compatible with most older equipment so that customers could upgrade via a firmware update. WPA builds on WEP encryption by scrambling the key and integrity-checking it to ensure it hasn't been tampered with. Additionally, it allows authentication using public key infrastructure (PKI) encryption, rather than relying on MAC address filtering. As we've already mentioned, MAC address filtering can be easily bypassed by sniffing the wireless traffic and picking MAC addresses up from the packets. Late last year, a third encryption standard, WPA2, was released, conforming to the 802.11i standard. WPA2 is basically similar to WPA, with the added security of the strong AES encryption protocol, required by some businesses and government agencies. WPA and WPA2 place an even bigger drag on wireless performance than WEP, and requires that ALL devices on the wireless net be set to WPA -- clients, the wireless router or access point, and any other relays or access points in between. No matter which encryption type you use, change your key as often as you can. It takes recording a certain amount of traffic to give crackers enough data to decode a key, so many businesses change keys on a regular schedule, presumably thwarting even determined hackers. Also, passwords do get written down and can fall into the wrong hands. For more on WPA encryption check out NetGear's excellent primer What's New in Security: WPA (Wi-Fi Protected Access). The Wi-Fi Alliance also has an information page on WPA2 6. Check frequently for rogue access points or clients attached to the network. Most Wi-Fi gateways have a status screen that shows the MAC addresses of all clients currently connected to the network, and some have logging capabilities that will keep track of wireless connections. If you spot unknown clients attached for lengths of time (not just passing by), change your WEP or WPA code, and scout around for where they might be located. Another way to monitor your network is with a packet sniffer like the free Ethereal. Packet sniffers show you all the traffic that's zipping around your net, and you'll see things like plain text messages and passwords flashing by heedlessly. It shockingly illustrates the weaknesses of common protocols like telnet, ftp, AIM and others. You'll not only find out if unauthorized people are using your network, you'll also see what THEY see when they are snooping around. Rogue clients aren't the only thing to look for, however. Rogue access points are dangerous as well, although more of a concern in public areas than in the home. Rogue access points are designed to mimic your regular wireless access point, and capture data sent through them. You can use a utility like NetStumbler or iStumbler for Mac to see them. See the page on protecting yourself at Wi-Fi hotspots for more details. 7. Use a strong firewall. The steps we've discussed so far focus on securing the wireless network, but once your wireless data reaches the access point, it becomes part of the wired net, and subject to any attacks or snooping that might come in through your broadband gateway (or from other users on your local wired net). Furthermore, WEP and WPA encryption only apply to data in the air, as soon as it passes through the Wi-Fi gateway, data is decrypted. Most home networking routers come with built-in firewall capabilities. The firewall is usually a basic port-blocking or packet-filtering firewall which lets you permit or deny incoming traffic on certain ports. The typical configuration is to block ALL incoming ports by default and then allow you to open ports for specific purposes. Stateful Packet Inspection (SPI) firewalls take things to a higher level still by actually examining network traffic for suspect activities and reporting attacks and intrusions. Unless you are running a Web or FTP server you shouldn't need any of the ports open, but some peer-to-peer file sharing networks and online games require communication over certain ports. Worms like MSBlast and Nachi were aimed at the Windows SMB (Server Message Block) and NetBIOS ports that are intended for directory, file and printer sharing across the network. Having your computer respond to NetBIOS inquiries can also give away valuable information that an attacker may use to gain access to your system or network. It is especially recommended that you block TCP ports 135, 137, 138, 139 and 445 from external access and that you disable NetBIOS over TCP/IP to prevent such attacks or leaks of pertinent information. You can also use a personal firewall like Zone Alarm Pro or Norton Personal Firewall that runs on your computer in addition to the network firewall. Personal firewalls provide an extra layer of security against outside hackers, as well as safeguard against snooping from within the local network. See the page on protecting yourself at public hotspots for more on personal firewalls. 8. Password your data. Often overlooked in a home environment, passwords provide another layer of security for your private data. You can generally password-protect and/or encrypt your computer, certain folders, or even specific files. Make sure your passwords are not easily guessed or written on a sticky note on the front of your monitor. Whenever possible, try to place private, confidential or otherwise sensitive documents in special folders that only you or those designated by you have access to. Older OSes like Windows 95 and 98 don't have password-protection capability built-in, but Windows 2000, Windows XP and Mac OS X all make it a relatively simple matter. In general, the longer the password the longer it will take someone to find it using password-cracking programs. Use words that aren't in the dictionary and that contain combinations of lower-case and upper-case letters, numbers and special characters. And change them if you have any reason to suspect they might have been violated, such as by a keystroke-capture program. (Most businesses require changing things like email passwords regularly.) If you are curious to see how easily your password can be cracked, check out tools like @Stake LC4 or Cain & Abel. 9. Separate your wired and wireless nets. If you're a network pro and have a small office network, consider doing a couple more things: change the default community names that ship with network management tools like SNMP so they can't be easily guessed; and put wireless access points on separate subnets with firewalls between them and the main network. 10. Turn off wireless devices when not in use. The final word of advice for home wireless networks is "Turn it off!" While it may seem like a pain, you'll sleep easier knowing that since your gateway, computer, laptop etc. are not turned on, no one can access them. Use a power strip to plug in all your devices, and just flip one switch when you get to work. In multiple-user households, you'll probably want to leave the broadband gateway on 24/7, but you can still turn off your own PC. A computer that isn't connected can't be hacked or compromised from the network. If you rely on dial-up Internet access this is not as big a concern

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Wi-Fi Security tips for public hotspots

Wi-Fi hotspots present a special set of security issues, notably unknown computers sharing the same local network with you. Unlike home or office networks, most public hotspots in hotels and cafes broadcast their SSIDs, lack WEP or WPA encryption, and don't bother with MAC address filtering. After all, turning on any of these functions would negate the "public" aspect of hotspots. That said, even if they used closed networks and encryption, making customers go through hoops to get connected, there would still be no way to tell a "legitimate" client from a "malicious" one out to hack other customers' data. Anyone with a credit card can sign up for hotspot service. So what can you do to protect yourself at a public hotspot? Plenty...

Top 10 Security Tips for Public Hotspots Make sure you're connected to a legitimate access point. Encrypt files before transferring or emailing them. Use a virtual private network (VPN). Use a personal firewall. Use anti-virus software. Update your operating system regularly. Be aware of people around you. Use Web-based email that employs secure http (https). Turn off file sharing. Password-protect your computer and important files. 1. Make sure you're connected to a legitimate access point! This first step is probably the least obvious, but one of the most important. Rogue access points in public areas have been springing up that have the same SSID as what you'd expect (such as "Wayport" or "tmobile"), but really connect directly to hijackers' databases to collect the passwords and usernames you use to sign in. Even worse, they can collect credit card data from people who sign up for new accounts. So don't connect in places where there is no sign for a legitimate provider, and check the list of available SSIDs to make sure you are connected to the right one. Don't set your wireless card to connect automatically to any available network. Turn off the ad-hoc mode (which lets other clients connect directly to you!). And turn off your Wi-Fi card entirely as soon as you are done. 2. Encrypt sensitive data. As you beam emails from your laptop to the wireless access point and back, or as you enter your username and password to check your bank account balances someone nearby can be intercepting those packets of data as they fly by. Much of the information -- even information that you might think should be encrypted -- is sent in clear text. That means that the person intercepting those packets may be able to read your emails or learn your passwords. While data sent to and from secure Web sites (those starting with https:) is generally protected, you can also use encryption in other contexts. If you are sending a sensitive file via email, for example, encrypt it first with a password. Most file compression programs, such as Allume's StuffIt Deluxe, offer encryption, and there are numerous freeware and shareware encryption programs as well. 3. Use a Virtual Private Network. One of the best ways to protect your data when using a public wireless network or hotspot is to use a virtual private network (VPN), such as JiWire SpotLock. A VPN establishes a private network across the public network by creating a tunnel between the two endpoints so that nobody in between can intercept the data. Many companies allow remote users to connect to corporate networks as long as they use VPN. This keeps the users' communications just as secure as if they were sitting at a desk in the building. If you don't have a corporate VPN, you can be secure at any hotspot using JiWire SpotLock. SpotLock's IPSec VPN is supported by almost all wireless routers, both public and private, and SpotLock also includes full Wi-Fi connection management. 4. Use a personal firewall. When you connect to a public wireless network you are joining a local network with other unknown computers. Having these computers on the same IP subnet makes them more dangerous than machines elsewhere on the Internet. Machines in your network and subnet range are able to more easily capture traffic between your computer and the wireless access point or attempt to connect with your computer and access your files and folders. To protect your computer you should run a personal firewall program. There are many excellent choices. Some, such as Zone Labs ZoneAlarm, Kerio's Personal Firewall, and the built-in Windows XP Firewall are available for free for home or personal use. You should not install them on your corporate laptop, however, without purchasing the proper licensing or consulting your IT manager. Security software vendors such as Symantec and McAfee also make commercial personal firewall products. A personal firewall will help you restrict the traffic allowed in and out of your computer. This protects you not only from attacks that originate outside of your network, but also those from other computers on the same network. Personal firewall software generally monitors both incoming and outgoing traffic, as well as applications trying to interact with other system processes or with the operating system. Should your computer somehow become compromised with a Trojan horse or backdoor program, a personal firewall application should flag the unusual communication attempts and alert you. Make sure you take the time to familiarize yourself with the product you choose and configure it properly to get the maximum protection without getting in the way of legitimate traffic and applications. 5. Use anti-virus software. When you are on your home network or even on your company network you can operate with a fair assurance that the other machines on the network with you are at least as protected as yours is against viruses and other malicious code. When you connect to a public network you have no such assurance. Suddenly it is more important than ever to have antivirus software installed. Of course, antivirus software is only as good as its last update. If you updated your antivirus software a month ago there are probably at least 10 and maybe 50 or more new viruses, worms and other malware that you aren't protected against. Make a special effort to go to the vendor's Web site and download the latest update any time you hear about a new high-risk or fast-spreading threat, and take advantage of the auto-update features now found in most such programs. 6. Keep your OS and apps up to date. It seems that almost every week there's a new "security patch" for various parts of the Windows operating system or Office programs. And it's not just Microsoft. Apple has its own fair share of security updates, as do most utility and business software vendors. Most of the malicious viruses and worms that have plagued users recently spread through email, so be especially cautious about opening attachments. Windows users should enable Automatic Updates or visit the Windows Update site to scan your system and identify patches you may be missing. Mac OS users should enable the automatic Software Update feature in System Preferences; and Linux/UNIX users can visit sites such asBugtraq or subscribe to receive bulletins and alerts from the Department of Homeland Security'sUS-CERT. 7. Be aware of people around you. When you're at an ATM, you make sure noone can see you type your PIN. Be just as careful about typing in your name and password at a Starbucks. You pay big bucks for your T-Mobile access! 8. Use Web-based email when you're connecting at a public hotspot, instead of Outlook, Eudora, or Apple Mail. Most ISPs these days let you send and receive email via a Web interface as well as downloading it into your email program. These Web sites generally use secure sockets layer (SSL) or other security protocols, which protect your data while it's being transmitted. 9. Make sure file sharing is off! On home networks, file sharing is frequently used to copy files back and forth between computers. On a public network, this is the last thing you want to have on, for obvious reasons. If necessary, put a sticky note on the edge of your computer screen reminding you to turn it off before you close your laptop. Just don't write your passwords on the same sticky note... 10. Use passwords for personal data. Our final tip: use strong passwords for sensitive files and folders, as well as for access to your computer as a whole. This is especially important for mobile warriors whose laptops are attractive theft targets. Consider keeping your most important data on an encrypted USB keychain storage device, so even if you lose your portable, you won't lose your presentation or email folder.

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What is WiFi?

If you have a network in your home or office, there are several different ways to connect the computers on your network together. The article How Home Networking Works covers all of the basic networking principles. WiFi is the wireless way to handle networking. It is also known as 802.11 networking and wireless networking. The big advantage of WiFi is its simplicity. You can connect computers anywhere in your home or office without the need for wires. The computers connect to the network using radio signals, and computers can be up to 100 feet or so apart.In this article, we will discuss two different aspects of WiFi. First we will discuss the basic technology that makes WiFi networking possible.

Then we will discuss the hardware you need to create a WiFi network, and help you understand how to set up and access a WiFi hotspot in your home. The Walkie-Talkie Network If you want to understand wireless networking at its simplest level, think about a pair of $5 walkie-talkies that you might purchase at Wal-Mart. These are small radios that can transmit and receive radio signals. When you talk into a Walkie-Talkie, your voice is picked up by a microphone, encoded onto a radio frequency and transmitted with the antenna. Another walkie-talkie can receive the transmission with its antenna, decode your voice from the radio signal and drive a speaker. Simple walkie-talkies like this transmit at a signal strength of about 0.25 watts, and they can transmit about 500 to 1,000 feet. Let's imagine that you want to connect two computers together in a network using walkie-talkie technology: You would equip each computer with a walkie-talkie. You would give each computer a way to set whether it wants to transmit or receive. You would give the computer a way to turn its binary 1s and 0s into two different beeps that the walkie-talkie could transmit and receive and convert back and forth between beeps and 1s/0s. This would actually work. The only problem would be that the data rate would be very slow. A $5 walkie-talkie is designed to handle the human voice (and it's a pretty scratchy rendition at that), so you would not be able to send very much data this way. Maybe 1,000 bits per second. WiFi's Radio Technology The radios used in WiFi are not so different from the radios used in $5 walkie-talkies. They have the ability to transmit and receive. They have the ability to convert 1s and 0s into radio waves and then back into 1s and 0s. There are three big differences between WiFi radios and Walkie-talkies: WiFi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz, while those that comply with the 802.11a standard transmit at 5 GHz. Normal walkie-talkies normally operate at 49 MHz. The higher frequency allows higher data rates. WiFi radios use much more efficient coding techniques that also contribute to the much higher data rates. For 802.11a and 802.11g, the technique is known as orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called Complementary Code Keying (CCK). See this page for details. The radios used for WiFi have the ability to change frequencies. 802.11b cards can transmit directly on any of three bands, or they can split the available radio bandwidth into dozens of channels and frequency hop rapidly between them. The advantage of frequency hopping is that it is much more immune to interference and can allow dozens of WiFi cards to talk simultaneously without interfering with each other.  Because they are transmitting at much higher frequencies than a Walkie-Talkie, and because of the encoding techniques, WiFi radios can handle a lot more data per second. 802.11b can handle up to 11 megabits per second (although 7 megabits per second is more typical, and 802.11b may fall back as low as 1 or 2 megabits per second if there is a lot of interference). 802.11a and 802.11g can handle up to 54 megabits per second (although 30 megabits per second is more typical). You might be wondering where the funny 802.11 nomenclature comes from. The Institute of Electrical and Electronics Engineers (IEEE) creates standards, and they number these standards in unique ways. The 802.11 standard covers wireless networks. The a, b and g notations identify different flavors of the 802.11 standard: 802.11b was the first version to reach the marketplace. It is the slowest and least expensive of the three. As mentioned above, 802.11b transmits at 2.4 GHz and can handle up to 11 megabits per second. 802.11a was next. It operates at 5 GHz and can handle up to 54 megabits per second. 802.11g is a mix of both worlds. It operates at 2.4Ghz (giving it the cost advantage of 802.11b) but it has the 54 megabits per second speed of 802.11a.  Fortunately, all of this radio technology is hidden in a WiFi card and is completely invisible. WiFi, in fact, is one of the easiest technologies that you will ever use. Adding WiFi to a Computer One of the best things about WiFi is how simple it is. Many new laptops already come with a WiFi card built in -- in many cases you don't have to do anything to start using WiFi. It is also easy to add a WiFi card to an older laptop or a desktop PC. Here's what you do: Buy a 802.11a, 802.11b or 802.11g network card. 802.11g has the advantage of higher speeds and good interoperability on 802.11b equipment. For a laptop, this card will normally be a PCMCIA card that you slide into a PCMCIA slot on your laptop. Or you can buy a small external adapter and plug it into a USB port. For a desktop machine, you can buy a PCI card that you install inside the machine, or a small external adapter that you connect to the computer with a USB cable. Install the card Install the drivers for the card Find an 802.11 hotspot Access the hotspot. A hotspot is a connection point for a WiFi network. It is a small box that is hardwired into the Internet. The box contains an 802.11 radio that can simultaneously talk to up to 100 or so 802.11 cards. There are many WiFi hotspots now available in public places like restaurants, hotels, libraries and airports. You can also create your own hotspot in your home, as we will see in a later section. Configuring WiFi On the newest machines, an 802.11 card will automatically connect with an 802.11 hotspot and a network connection will be established. As soon as you turn on your machine, it will connect and you will be able to browse the Web, send email, etc. using WiFi. On older machines you often have to go through this simple 3-step process to connect to a hotspot: Access the software for the 802.11 card -- normally there is an icon for the card down in the system tray at the bottom right of the screen. Click the "Search button" in the software. The card will search for all of the available hotspots in the area and show you a list. Double-click on one of the hotspots to connect to it. On ancient 802.11 equipment, there is no automatic search feature. You have to find what is known as the SSID of the hotspot (usually a short word of 10 characters or less) as well as the channel number (an integer between 1 and 11) and type these two pieces of information in manually. All the search feature is doing is grabbing these two pieces of information from the radio signals generated by the hotspot and displaying them for you. WiFi Security WiFi hotspots can be open or secure. If a hotspot is open, then anyone with a WiFi card can access the hotspot. If it is secure, then the user needs to know a WEP key to connect. WEP stands for Wired Equivalent Privacy, and it is an encryption system for the data that 802.11 sends through the air. WEP has two variations: 64-bit encryption (really 40-bit) and 128-bit encryption (really 104-bit). 40-bit encryption was the original standard but was found to be easily broken (see this page for an explanation). 128-bit encryption is more secure and is what most people use if they enable WEP. For a casual user, any hotspot that is using WEP is inaccessible unless you know the WEP key. If you are setting up a hotspot in your home, you may want to create and use a 128-bit WEP key to prevent the neighbors from casually eavesdropping on your network. Whether at home or on the road, you need to know the WEP key, and then enter it into the WiFi card's software, to gain access to the network. Setting Up a Hotspot in Your Home It is very easy to set up a WiFi hotspot in your own home. You can do it in one of two ways: If you already have several computers hooked together on an Ethernet network and want to add a wireless hotspot to the mix, you can purchase a Wireless Access Point and plug it into the Ethernet network. If you are setting up a network in your home for the first time, or if you are upgrading, you can buy a Wireless Access Point Router. This is a single box that contains: 1) a port to connect to your cable modem or DSL modem, 2) a router, 3) an Ethernet hub, 4) a firewall and 5) a wireless access point. You can connect the computers in your home to this box either with traditional Ethernet cables or with wireless cards. Either way, once you turn your Wireless Access Point on, you will have a WiFi hotspot in your house. In a typical home, your new hotspot will provide coverage for about 100 feet (30.5 meters) in all directions, although walls and floors do cut down on the range. Even so, you should get good coverage throughout a typical home. For a large home, you can buy inexpensive signal boosters to increase the range of the Hotspot.  If you are setting up your 802.11 network from scratch, you will have to choose between 802.11a, 802.11b and 802.11g. 802.11b is slightly less expensive, but it is the slowest of the three options. For home use, 802.11g costs just a little more, but is up to 5 times faster. If you will be doing a lot of file transfers between computers in your home, 802.11g is definitely the way to go.  Configuring a New Hotspot in your Home Most wireless access points come with default values built-in. Once you plug them in, they start working with these default values in 90 percent of the cases. However, you may want to change things. You normally get to set three things on your access point: The SSID -- it will normally default to the manufacturer's name (e.g. "Linksys" or "Netgear"). You can set it to any word or phrase you like. The channel -- normally it will default to channel 6. However, if a nearby neighbor is also using an access point and it is set to channel 6, there can be interference. Choose any other channel between 1 and 11. An easy way to see if your neighbors have access points is to use the search feature that comes with your wireless card. The WEP key -- The default is to disable WEP. If you want to turn it on, you have to enter a WEP key and turn on 128-bit encryption. Access points come with simple instructions for changing these three values. Normally you do it with a Web browser. Once it is configured properly, you can use your new hotspot to access the Internet from anywhere in your home. For more information on wireless networking and related topics, check out the links on the following page.

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How To Steal Wi-Fi

When I moved into a new neighborhood last week, I expected the usual hassles. Then I found out I'd have to wait more than a month for a DSL line. I started convulsing. If I don't have Net access for even one day, I can't do my job. So, what was I supposed to do? There's an Internet café on the next block, but they close early. I had no choice—it was time to start sneaking on to my neighbors' home networks.

Every techie I know says that you shouldn't use other people's networks without permission. Every techie I know does it anyway. If you're going to steal—no, let's say borrow—your neighbor's Wi-Fi access, you might as well do it right. Step one: Lose the guilt. The FCC told me that they don't know of any federal or state laws that make it illegal to log on to an open network. Using someone's connection to check your e-mail isn't like hacking into their bank account. It's more like you're borrowing a cup of sugar. (Unless you hog their bandwidth by watching lots of streaming video—that's like hijacking a sugar truck.)

In the end, it's your neighbor's Internet service provider—not your neighbor—who will pay for the added traffic, and the ISP has already factored a small amount of line-sharing into their price plan. It is true that your surfing could cause the folks next door to break their service contract—many broadband providers do specifically forbid home customers from sharing a connection. But let's deal with those abstract ethical issues later—you have important mail to answer!

If you want to find a Wi-Fi network,don't start by looking on the sidewalk for chalk marks. "Warchalking," a technique for writing symbols in public places to alert neighbors to nearby wireless access points, is a cool concept that's been undermined by the fact that no one has ever used it. The best method to find some free wireless is to treat your laptop like a cell phone. Since Wi-Fi and cell phone signals travel on a similar radio frequency, the same tricks you use for getting a better phone connection might work on your computer. Sit near a window, since Wi-Fi signals travel better through glass than through solid walls. Stay away from metal objects. Pay close attention to your laptop's orientation—rotating your machine just a few degrees could help you pick up a network that you couldn't see before. Raise your laptop over your head, put it flat on the floor, tilt it sideways while leaning halfway out the window—get out the divining rod if you have to. You might get a reputation for being some sick laptop yoga freak, but isn't free Internet worth it?

If you live downtown or in a suburb where the houses are close together, a few minutes of laptop gymnastics will probably reveal several Wi-Fi networks. Certain names are a giveaway that a network probably won't be password-protected. Look for "linksys," "default," "Wireless," "NETGEAR," "belkin54g," and "Apple Network 0273df." These are the default network names for the most popular wireless routers. If a network owner hasn't taken the time to change the default name, that's a good clue that they probably won't have a password either. You should also look for signs of hacker culture. Since hackers love giving away Net access, an all-lowercase name like "hackdojo" is most likely an invitation to log on. On the other hand, a name in all caps is typically a network under corporate lockdown.

If you do get prompted for a password, try "public"—that's the default on many of Apple's AirPort units. You can also try common passwords like "admin," "password," and "1234"—or just check out this exhaustive list of default passwords. You should also try using the name of the network in the password space. A generic password could mean that the network's owner didn't have the sense to pick something less obvious or that they've decided to welcome outsiders. But who cares? You're in. And again, there's no specific law barring you from guessing the password, as long as you don't crack an encrypted network and read other people's transmissions.

You can tell that you've successfully joined a wireless network when your laptop's IP address changes as it's assigned a local number by the network's router. To watch it happen on a PC, keep the Network control panel in Windows open; if you have an Apple notebook, look at the Network section of the System Preferences program. (And if you're running Linux, I don't need to tell you where to look.) Once your laptop has an IP address, your next hurdle is getting DNS to work. DNS stands for Domain Name Service—it's what translates Internet domains like "slate.com" into IP addresses like 207.46.141.216. On most networks, DNS works automatically. But if you get a browser error like "Cannot find server," go back to your network menus and configure your laptop to use a public name server—144.162.120.230 in Dallas, for instance.

Once DNS is working, you should be good to go. While you should be able to surf the Web with no problems, you may have trouble sending mail from Outlook or other desktop programs because of restrictions on e-mail routing that have been set up to stop spammers. If you have problems, just use a Web-based mail service like Hotmail or Gmailinstead.

Keep in mind that the neighbors may not be thrilled that you're sharing the line. One guy next door to my new building shut off his network the day after I moved in, probably because he got spooked by all those blinking LEDs on his router. Even neighbors who are happy to share may see you in a different light if they check their router's URL logs and find a few hundred hits on porn sites. While your browsing will show up under an anonymous address, the short range of Wi-Fi means that they'll at least be able to figure out that one of the laptop owners within 100 feet of their living room is a stuffed animal fetishist. (As a San Franciscan, I need to point out that a stuffed animal fetish is perfectly normal. It's your neighbors who have the problem.)

Since everyone isn't as eager to share their network as I am, it's only fair to explain that there's an incredibly easy way to keep neighbors and drive-by geeks off your network. All you have to do is set a password that isn't as obvious as "1234." There's an eye-glazing list of Wi-Fi security measures you can implement to block overachieving Russian teens from monitoring your keystrokes, but in real life the only people sniffing your wireless signal are jerks like me who need a place to log on until the phone company wires the apartment. An unguessable password sends as clear a message as a shot of Mace: Go find a Starbucks, creep.

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