What is Bluetooth?
Bluetooth is a radio frequency based cable replacement technology developed in 1994. It is designed to be an inexpensive wireless personal networking system for all classes of portable devices such as laptops, PDA's (Personal digital assistants), mobile phones and headsets. Bluetooth can also replace cabling in a more static environment i.e. between desktop computers and printers. A device has to be Bluetooth enabled (i.e. contain a Bluetooth chip) to be able to use a Bluetooth connection.
What is the range of Bluetooth?
Bluetooth devices can be in 3 different power classes:
- Class 3: The lowest power and the max range of this is 10m (30 feet)
- Class 2: Max range is about 50m (150ft)
- Class 1: Max range is about 100m (300ft)
These ranges can be affected by environmental conditions i.e. furniture, walls, people so ranges can easily be reduced. Bluetooth is not a line of sight connection so it can be used through walls and floors. Bluetooth is faster than an ISDN connection but slower than an IR (infra red) connection used on a laptop - a normal Bluetooth connection is about the same speed as a home broadband connection. It is a common misconception that all bluetooth devices can connect to any other device and browse the information on it. This cannot be done without the user setting the device to do so. Bluetooth security has various levels of authentication including pin code entry and up to 128-bit encryption.
What is Wi-Fi?
Wi-Fi began appearing in products in late 1998. Wi-Fi is wireless networking. The ability to connect to a network or PC using radio signals. It's faster and has a greater range than bluetooth, and is ideal for home or office connectivity. Using a Wi-Fi setup with your PDA or laptop means that you can share a broadband Internet connection, share files, printer or storage area between computer users.
The radios used for Wi-Fi communication are very similar to the radios used for walkie-talkies, cell phones and other devices. They can transmit and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. But Wi-Fi radios have a few notable differences from other radios.
They transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data.
They use 802.11 networking standards, which come in several flavors:
- 802.11a transmits at 5 GHz and can move up to 54 megabits of data per second. It also uses orthogonal frequency-division multiplexing (OFDM), a more efficient coding technique that splits that radio signals into several sub-signals before they reach a receiver. This greatly reduces interference.
- 802.11b is the slowest and least expensive standard. For a while, its cost made it popular, but now it's becoming less common as faster standards become less expensive. 802.11b transmits in the 2.4 GHz frequency band of the radio spectrum. It can handle up to 11 megabits of data per second, and it uses complementary code keying (CCK) modulation to improve speeds.
- 802.11g transmits at 2.4 GHz like 802.11b, but it's a lot faster -- it can handle up to 54 megabits of data per second. 802.11g is faster because it uses the same OFDM coding as 802.11a.
- 802.11n is the newest standard that is widely available. This standard significantly improves speed and range. For instance, although 802.11g theoretically moves 54 megabits of data per second, it only achieves real-world speeds of about 24 megabits of data per second because of network congestion. 802.11n, however, reportedly can achieve speeds as high as 140 megabits per second. The standard is currently in draft form -- the Institute of Electrical and Electronics Engineers (IEEE) plans to formally ratify 802.11n by the end of 2009.
Other 802.11 standards focus on specific applications of wireless networks, like wide area networks (WANs) inside vehicles or technology that lets you move from one wireless network to another seamlessly.
Wi-Fi radios can transmit on any of three frequency bands. Or, they can "frequency hop" rapidly between the different bands. Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously.
List of applications
Following are some of the latest applications which become very famous.
- Wireless communication between computers in a limited space and where low bandwidth is necessary.
- Wireless networking with personal computers whether input or output devices, most common used devices are mouse, keyboard and printer.
- Share files, calendar appointments, contact details, and reminders between devices.
- In test equipment it is the replacement of mostly used wired serial communications. Equipments such as medical equipments, GPS receivers, traffic control devices, and bar code scanners.
- For controls where infrared was commonly used.
- For low bandwidth applications where higher USB bandwidth is not compulsory and cable free connection can be used.
- The transfer of small advertisements from bluetooth enabled advertising posters to other new Bluetooth devices.
- Wireless connection between two modern ethernet networks.
- Three seventh generation game consoles such as Sony's play station 3, Nintendo's Wii and the new one PSP Go use bluetooth for their relevant wireless game controllers.
- Dial up internet access on PC's or PDAs using a data capable cell phone as a wireless modem like Novatel mifi.
- Short range transmission of health sensor data from medical devices to mobile phone, set top box or dedicated telehealth devices.
Bluetooth vs. Wi-Fi
Bluetooth and Wi-Fi have many applications setting up networks, printing, or transferring files. Wi-Fi is proposed for resident equipment and its applications. The category of applications is outlined as wireless local area networks (WLAN). Wi-Fi is intended as an alternative for cabling for general local area network access in work areas. Bluetooth is intended for non resident equipment and its applications. The category of applications is outlined as the wireless personal area network (WPAN). Bluetooth is a replacement for cabling in a variety of personally carried applications in any ambience. Bluetooth technology costs a third of Wi-Fi to implement. Bluetooth is more secure than Wi-Fi as it covers shorter distances and has a 2 level password protection. Wi-Fi is less secure; it has all the risks associated with any other network. If someone accesses one part, the rest can also be accessed. Power consumption differs from each other as bluetooth consumption is less then Wi-Fi. In order to use bluetooth a device must be compatible with certain Bluetooth profiles. Bluetooth has much compatibility issues then Wi-Fi. Bluetooth technology uses a fifth of the power of Wi-Fi. The Wi-Fi alliance tests and certifies 802.11 based wireless equipment.
Bluetooth uses frequency hopping technology to ensure transaction transmission by leveraging the entire spectrum of 2.4GHz to 2.4835GHz. This increases the likelihood of successful transmission due to a low sensibility to radio perturbations. Wi-Fi does not use frequency hopping therefore users may experience a change in performance in congested wireless environments. In terms of network capacity, Wi-Fi is more flexible as theoretically it is only limited by the number of IP addresses, where as Bluetooth is limited to 7 devices (Piconet network). Practically, Wi-Fi network size depends on the access point (average of 32 devices). But clearly the more devices there are on the network, the more risk of congestion there is. Note that both Bluetooth and Wi-Fi (802.11b/g) are using the same radio band (2.45 GHz) to exchange data Wi-Fi is a traditional Ethernet network, and requires configuration to set up shared resources, transmit files, and to set up audio links for example headsets and hands free devices. Wi-Fi uses the same radio frequencies as Bluetooth, but with higher power, resulting in a stronger connection. Wi-Fi is sometimes called wireless Ethernet. This description is accurate as it also provides an indication of its relative strengths and weaknesses. Wi-Fi requires more setup but is better suited for operating full-scale networks. It enables a faster connection and better range from the base station.
Bluetooth exists in many products, such as telephones, keyboards, printers, mouses, the Wii, PlayStation 3, PSP Go, and in some high definition watches, modems and headsets. The technology is useful when transferring information between two or more devices that are near each other in low-bandwidth situations. Bluetooth is commonly used to transfer sound data with telephones. Bluetooth protocols simplify the discovery and setup of services between devices. Bluetooth devices can advertise all of the services they provide. This makes using services easier because more of the security, network address and permission configuration can be automated than with many other network types. Bluetooth devices operate in the 2.45 Gigahertz frequency range. Other devices currently operate in this frequency range. This low power limits the range of a Bluetooth device to about 10 meters. A frequency hopping scheme allows devices to communicate even in areas with a great deal of electromagnetic interference. Bluetooth devices have a maximum transmission rate of only 1 Mbps up to 2 Mbps in the second generation of the technology of which about 20 percent of this capacity is used for data headers and handshaking information. The main difference between the two technologies is that Bluetooth devices communicate one-on-one with each other, whereas Wi-Fi devices communicate with any other device through a wireless router. Bluetooth is generally used for transmitting audio, such as from your cell phone to your wireless earpiece. Wi-Fi is generally used for transmitting internet signals from your cable or DSL modem to and from your computer.
By comparison, Wi-Fi wireless LAN adapters are much more powerful and capable of reaching data transmission rates approaching 54Mbps. The most popular Wi-Fi standard is the one used in your D-Link router, 802.11b. This version provides users with 11 Mbps transmission speeds and also operates in the 2.4 GHz band. Products based on this specification have very good range and can commonly transmit data at distances of well over 100 feet. So as you can see, Bluetooth and Wi-Fi wireless technology were designed for two completely different purposes. Bluetooth products make it easy to connect various electronic devices to each other without the need for clumsy cables, while 802.11-based Wi-Fi products were designed as a replacement for or extension of the wired LAN.
As a conclusion, in terms of coverage Wi-Fi is the technology for big network environments while bluetooth gives optimal performances in single network configuration.The interference and co-existence issues that exist with co-located Bluetooth and WLAN devices are amongst the most difficult in radio design because of the low power, cost and size constraints. Since neither standard contains a method for coordination, a mix of RF design practices and proprietary coordination mechanisms are used to ensure interoperability with negligible performance impact to the end-user.
Wireless technology may seem like the next step in networking to an extent cannot be used to their full potential due to interference from weather or other phenomena that may alter radio waves. There are many who are refining and developing wireless networking to make it global such as WiMAX that is also a compliment to Wi-Fi and may help expand Wi-Fi's capabilities as well.
One can look to the future and see wireless technology as being a competitor in networking because of how quickly many business are trying to take advantage of them.