The following topics are available here under wireless networking:
WiFi
WiMAX
RFID
BLUETOOTH
UWB
WIRELESS SECURITY
WiFi
WiFi is the short form for Wireless Fidility. Wi-Fi is the name for a collection of standards defined by the Wi-Fi alliance [20]. The standards are defined for use in a local area network (LAN), commonly used by personal computers. It is based on the IEEE 802.11 specifications, which is the only specification used for Wi-Fi for now, although new ones are under development.
A Wireless LAN ( WLAN or WiFi ) is a data transmission system designed to provide location independent network access between computing devices by using radio waves rather than a cable infrastructure. In the corporate enterprise, wireless LANs are usually implemented as the final link between the existing wired network and a group of client computers, giving these users wireless access to the full resources and services of the corporate network across a building or campus setting.
The widespread acceptance of WLANs depends on industry standardization to ensure product compatibility and reliability among the various manufacturers. The 802.11 specification [ IEEE Std 802.11 (ISO/IEC 8802-11: 1999) ] as a standard for wireless LANS was ratified by the Institute of Electrical and Electronics Engineers (IEEE) in the year 1997. This version of 802.11 provides for 1 Mbps and 2 Mbps data rates and a set of fundamental signaling methods and other services. Like all IEEE 802 standards, the 802.11 standards focus on the bottom two levels the ISO model, the physical layer and link layer (see figure below). Any LAN application, network operating system, protocol, including TCP/IP and Novell NetWare, will run on an 802.11-compliant WLAN as easily as they run over Ethernet.
Normally Wi-Fi setup contains one or more Access Points (APs) and one or more clients. An AP broadcasts its SSID (Service Set Identifier, Network name) via packets that are called beacons , which are broadcasted every 100ms. The beacons are transmitted at 1Mbps, and are relatively short and therefore are not of influence on performance. Since 1Mbps is the lowest rate of Wi-Fi it assures that the client who receives the beacon can communicate at at least 1Mbps. Based on the settings (i.e. the SSID), the client may decide whether to connect to an AP. Also the firmware running on the client Wi-Fi card is of influence. Say two AP's of the same SSID are in range of the client, the firmware may decide based on signal strength ( Signal-to-noise ratio ) to which of the two AP's it will connect. The Wi-Fi standard leaves connection criteria and roaming totally open to the client. This is a strength of Wi-Fi, but also means that one wireless adapter may perform substantially better than the other. Since Windows XP there is a feature called zero configuration which makes the user show any network available and let the end user connect to it on the fly. In the future wireless cards will be more and more controlled by the operating system. Microsoft's newest feature called SoftMAC will take over from on-board firmware. Having said this, roaming criteria will be totally controlled by the operating system. Wi-Fi transmits in the air, it has the same properties as a non-switched ethernet network. Even collisions can therefore appear like in non-switched ethernet LAN's.
Advantages of Wi-Fi
Unlike packet radio systems, Wi-Fi uses unlicensed radio spectrum and does not require regulatory approval for individual deployers.
Allows LANs to be deployed without cabling, potentially reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.
Wi-Fi products are widely available in the market. Different brands of access points and client network interfaces are interoperable at a basic level of service.
Competition amongst vendors has lowered prices considerably since their inception.
Wi-Fi networks support roaming, in which a mobile client station such as a laptop computer can move from one access point to another as the user moves around a building or area.
Many access points and network interfaces support various degrees of encryption to protect traffic from interception.
Wi-Fi is a global set of standards. Unlike cellular carriers, the same Wi-Fi client works in different countries around the world.
WiMAX
WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband technology, which supports point to multi-point (PMP) broadband wireless access over long distances with high throughput.
WiMax is basically a new shorthand term for IEEE Standard 802.16, which was designed to support the European standards. 802.16's predecessors (like 802.11a) were not very acc ommodative of the European standards, per se.
The IEEE wireless standard has a range of up to 30 miles, and can deliver broadband at around 75 megabits per second. This is theoretically, 20 times faster than a commercially available wireless broadband. The 802.16, WiMax standard was published in March 2002 and provided updated information on the Metropolitan Area Network (MAN) technology. The extension given in the March publication, extended the line-of-sight fixed wireless MAN standard, focused solely on a spectrum from 10 GHz to 60+ GHz.
This extension provides for non-line of sight access in low frequency bands like 2 - 11 GHz. These bands are sometimes unlicensed. This also boosts the maximum distance from 31 to 50 miles and supports PMP (point to multipoint) and mesh technologies.
The IEEE approved the 802.16 standards in June 2004, and three working groups were formed to evaluate and rate the standards.
WiMax can be used for wireless networking like the popular WiFi. WiMax, a second-generation protocol, allows higher data rates over longer distances, efficient use of bandwidth, and avoids interference almost to a minimum. WiMax can be termed partially a successor to the Wi-Fi protocol, which is measured in feet, and works, over shorter distances.
WiMAX can be used for a number of applications, including last mile broadband connections, hotspots and cellular backhaul, and high-speed enterprise connectivity for business.
Radio Frequency Identification (RFID)
WiFi
WiMAX
RFID
BLUETOOTH
UWB
WIRELESS SECURITY
WiFi
WiFi is the short form for Wireless Fidility. Wi-Fi is the name for a collection of standards defined by the Wi-Fi alliance [20]. The standards are defined for use in a local area network (LAN), commonly used by personal computers. It is based on the IEEE 802.11 specifications, which is the only specification used for Wi-Fi for now, although new ones are under development.
A Wireless LAN ( WLAN or WiFi ) is a data transmission system designed to provide location independent network access between computing devices by using radio waves rather than a cable infrastructure. In the corporate enterprise, wireless LANs are usually implemented as the final link between the existing wired network and a group of client computers, giving these users wireless access to the full resources and services of the corporate network across a building or campus setting.
The widespread acceptance of WLANs depends on industry standardization to ensure product compatibility and reliability among the various manufacturers. The 802.11 specification [ IEEE Std 802.11 (ISO/IEC 8802-11: 1999) ] as a standard for wireless LANS was ratified by the Institute of Electrical and Electronics Engineers (IEEE) in the year 1997. This version of 802.11 provides for 1 Mbps and 2 Mbps data rates and a set of fundamental signaling methods and other services. Like all IEEE 802 standards, the 802.11 standards focus on the bottom two levels the ISO model, the physical layer and link layer (see figure below). Any LAN application, network operating system, protocol, including TCP/IP and Novell NetWare, will run on an 802.11-compliant WLAN as easily as they run over Ethernet.
Normally Wi-Fi setup contains one or more Access Points (APs) and one or more clients. An AP broadcasts its SSID (Service Set Identifier, Network name) via packets that are called beacons , which are broadcasted every 100ms. The beacons are transmitted at 1Mbps, and are relatively short and therefore are not of influence on performance. Since 1Mbps is the lowest rate of Wi-Fi it assures that the client who receives the beacon can communicate at at least 1Mbps. Based on the settings (i.e. the SSID), the client may decide whether to connect to an AP. Also the firmware running on the client Wi-Fi card is of influence. Say two AP's of the same SSID are in range of the client, the firmware may decide based on signal strength ( Signal-to-noise ratio ) to which of the two AP's it will connect. The Wi-Fi standard leaves connection criteria and roaming totally open to the client. This is a strength of Wi-Fi, but also means that one wireless adapter may perform substantially better than the other. Since Windows XP there is a feature called zero configuration which makes the user show any network available and let the end user connect to it on the fly. In the future wireless cards will be more and more controlled by the operating system. Microsoft's newest feature called SoftMAC will take over from on-board firmware. Having said this, roaming criteria will be totally controlled by the operating system. Wi-Fi transmits in the air, it has the same properties as a non-switched ethernet network. Even collisions can therefore appear like in non-switched ethernet LAN's.
Advantages of Wi-Fi
Unlike packet radio systems, Wi-Fi uses unlicensed radio spectrum and does not require regulatory approval for individual deployers.
Allows LANs to be deployed without cabling, potentially reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.
Wi-Fi products are widely available in the market. Different brands of access points and client network interfaces are interoperable at a basic level of service.
Competition amongst vendors has lowered prices considerably since their inception.
Wi-Fi networks support roaming, in which a mobile client station such as a laptop computer can move from one access point to another as the user moves around a building or area.
Many access points and network interfaces support various degrees of encryption to protect traffic from interception.
Wi-Fi is a global set of standards. Unlike cellular carriers, the same Wi-Fi client works in different countries around the world.
WiMAX
WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband technology, which supports point to multi-point (PMP) broadband wireless access over long distances with high throughput.
WiMax is basically a new shorthand term for IEEE Standard 802.16, which was designed to support the European standards. 802.16's predecessors (like 802.11a) were not very acc ommodative of the European standards, per se.
The IEEE wireless standard has a range of up to 30 miles, and can deliver broadband at around 75 megabits per second. This is theoretically, 20 times faster than a commercially available wireless broadband. The 802.16, WiMax standard was published in March 2002 and provided updated information on the Metropolitan Area Network (MAN) technology. The extension given in the March publication, extended the line-of-sight fixed wireless MAN standard, focused solely on a spectrum from 10 GHz to 60+ GHz.
This extension provides for non-line of sight access in low frequency bands like 2 - 11 GHz. These bands are sometimes unlicensed. This also boosts the maximum distance from 31 to 50 miles and supports PMP (point to multipoint) and mesh technologies.
The IEEE approved the 802.16 standards in June 2004, and three working groups were formed to evaluate and rate the standards.
WiMax can be used for wireless networking like the popular WiFi. WiMax, a second-generation protocol, allows higher data rates over longer distances, efficient use of bandwidth, and avoids interference almost to a minimum. WiMax can be termed partially a successor to the Wi-Fi protocol, which is measured in feet, and works, over shorter distances.
WiMAX can be used for a number of applications, including last mile broadband connections, hotspots and cellular backhaul, and high-speed enterprise connectivity for business.
Radio Frequency Identification (RFID)
Radio Frequency Identification ( RFID ) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders . An RFID tag is a small object that can be attached to or incorporated into a product, animal, or person. RFID tags contain silicon chips and antennas to enable them to receive and respond to radio -frequency queries from an RFID transceiver . Passive tags require no internal power source, whereas active tags require a power source. Typical RFID tags usually can not store more than 2KB of data [22], limiting the amount of information that they can send.
The range of RFID tags range from just a few millimeters to several meters using passive tags (tags without their own energy source), to 100 meters or more with active tags (tags that are powered by an energy source). The range also depends on other factors, like the RFID reader used and interference. The transfer rate is also highly varying, depending on the implementation, frequency used, whether active tags or passive tags are used, and possibly other factors.
Types of RFID Tags:
RFID tags can be either passive , semi-passive (also known as semi-active ), or active .
Passive: Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming radio frequency signal provides just enough power for the CMOS integrated circuit (IC) in the tag to power up and transmit a response. Most passive tags signal by backscattering the carrier signal from the reader. This means that the aerial (antenna) has to be designed to both collect power from the incoming signal and also to transmit the outbound backscatter signal. The response of a passive RFID tag is not just an ID number (GUID): tag chip can contain nonvolatile EEPROM(Electrically Erasable Programmable Read-Only Memory) for storing data. Lack of an onboard power supply means that the device can be quite small: commercially available products exist that can be embedded under the skin.
Semi-passive: Semi-passive RFID tags are very similar to passive tags except for the addition of a small battery. This battery allows the tag IC to be constantly powered. This removes the need for the aerial to be designed to collect power from the incoming signal. Aerials can therefore be optimized for the backscattering signal. Semi-passive RFID tags are faster in response and therefore stronger in reading ratio compared to passive tags.
Active: Unlike passive and semi-passive RFID tags, active RFID tags (also known as beacons ) have their own internal power source which is used to power any ICs and generate the outgoing signal. They are often called beacons because they broadcast their own signal. They may have longer range and larger memories than passive tags, as well as the ability to store additional information sent by the transceiver. To economize power consumption, many beacon concepts operate at fixed intervals. At present, the smallest active tags are about the size of a coin. Many active tags have practical ranges of tens of meters, and a battery life of up to 10 years.
Some applications of RFID are:
- Person Identification
- Food Production Control
- Vehicle Parking Monitoring
- Toxic Waste Monitoring
- Valuable Objects Insurance Identification
- Asset Management
- Access Control
- Mass transit ticketing (Ang sa MRT bala!)
Bluetooth
Bluetooth is the technology using short range radio links, intended to replace the cables connecting portable/fixed electronic devices. Using this technology, users can have all mobile and fixed computer devices be totally coordinated. The standard defines a uniform structure for a wide range of devices to communicate with each other, with minimal user effort. Its key features are robustness, low complexity, low power and low cost. The technology also offers wireless access to LANs, PSTN, the mobile phone network and the Internet for a host of home appliances and portable handheld interfaces.
Bluetooth is a short-distance wireless technology with the following technical characteristics:
- license-free 2.4 GHz frequency band
- 400 kbps of data symmetrically or 700 to 150 kbps of data asymmetrically
- Range approximately 10 m at 1 mW transmitting power, approximately 100 m (in the open) at 100 mW
Bluetooth supports two kinds of links : Asynchronous Connectionless (ACL) links for data transmission and Synchronous Connection oriented (SCO) links for audio/voice transmission. The gross Bluetooth data rate is 1 Mbps while the maximum effective rate on an asymmetric ACL link is 721 Kbps in either direction and 57.6 Kbps in the return direction. A symmetric ACL link allows data rates of 432.6 Kbps. Bluetooth also supports up to three 64Kbps SCO channels per device. These channels are guaranteed bandwidth for transmission.
The Bluetooth core system consists of an RF transceiver, baseband, and protocol stack. The system offers services that enable the connection of devices and the exchange of a variety of data classes between these devices. During typical bluetooth operation, a physical radio channel is shared by a group of devices that are synchronized to a common clock and frequency hopping pattern. One device provides the synchronization reference and is known as the master. All other devices are known as slaves. A group of devices synchronized in this fashion form a piconet. This is the fundamental form of communication for Bluetooth wireless technology.
The transmission range of Bluetooth ranges depending on the power class of the implementation. It has three power classes, where class 2, with a range of about 10 meters is the most common. The others are class 1, up to 100 meters, and the rarely used class 3, which has a range of 10 cm, up to a maximum of 1 meter. The maximum speed of Bluetooth transfers is 723.1 kilobit/s in
version 1.1 - 1.2, and 2.1 megabit/s in version 2.0
Each Bluetooth device has a unique address, also called Bluetooth ID or device ID. This ID is usually not shown to users, as the more user friendly customizable Bluetooth name is shown
instead.
Bluetooth could also be used in home networking applications. With increasing numbers of homes having multiple PCs, the need for networks that are simple to install and maintain, is growing. There is also the commercial need to provide "information push" capabilities, which is important for handheld and other such mobile devices and this has been partially incorporated in Bluetooth. Bluetooth's main strength is its ability to simultaneously handle both data and voice transmissions, allowing such innovative solutions as a mobile hands-free headset for voice calls, print to fax capability, and automatically synchronizing PDA, laptop, and cell phone address book applications. One popular use of Bluetooth is for wireless headsets. A Bluetooth headset would have a Bluetooth radio built in, allowing it to connect to mobile phones or computers, so that people canuse the headset without connecting it with a cable.
Bluetooth is competing against two other major methods of wireless networking: IrDA and WiFi. However, WiFi is most useful as a replacement for LANs and IrDa is limited by its need for an unobstructed line-of-sight between connecting devices.
Applications
The following are the areas where Bluetooth can be used:
- Replacing serial cables by radio links
- "Wearable" networks/PANs
- Desktop/Room Wireless Networking
- HotSpot Wireless Networking
Medical: Transfer of measured values from training units to analytical systems, Patient data monitoring
Automotive: Remote control of audio/video equipment, Hands-free telephony
POS (Point-of-sale) payments: Payments by mobile phone
Ultra Wideband (UWB)
Ultra Wideband or UWB is a technique based on transmitting very-short-duration pulses, often of duration of only nanoseconds or less, whereby the occupied bandwidth goes to very large values. This allows it to deliver data rates in excess of 100 Mbit/s, while using a small amount of power and operating in the same bands as existing communications without producing significant interference. However it is not limited to wireless communication, UWB can also use mains-wiring, coaxial cable or twisted-pair cables to communicate - with potential to deliver data faster than 1 gigabit per second.
Ultrawideband (UWB) technology offers great opportunities for short-range wireless multimedia networking. The usefulness of Ultra-Wideband will not just end with high-quality multimedia. It's raw high-speed performance will enable wireless to finally deliver on true device synchronization. Keeping your contacts, calendars, music and movies all in sync could be done so quickly users might begin to forget their content was originally on separate devices.
Unlike conventional wireless systems, which use narrowband modulated carrier waves to transmit information, Ultra-Wideband transmits over a wide swath of radio spectrum, using a series of very narrow and low-power pulses. The combination of broader spectrum, lower power and pulsed data means that Ultra-Wideband causes signi•cantly less interference than conventional narrowband radio solutions while safely coexisting with other wireless technologies on the market.
Applications
Ultra-Wideband allows consumers the hope of eliminating the maze of wires connecting electronic products in their home, including large screen displays, set-top boxes, speakers, televisions, digital video recorders, PCs/laptops, digital cameras, smartphones and more. Products that include Ultra-Wideband are expected to:
Build a home theater environment without cables
Share live multimedia content between televisions
Instantaneously transfer the images from a digital camera to another product
Quickly synchronize ultra high capacity digital audio players
Share wireless video between a computer and a separate monitor
Wireless Security
Wireless communications offer organizations and users many benefits such as portability and flexibility, increased productivity, and lower installation costs. Wireless technologies cover a broad range of differing capabilities oriented toward different uses and needs. Wireless local area network (WLAN) devices, for instance, allow users to move their laptops from place to place within their offices without the need for wires and without losing network connectivity. Less wiring means greater flexibility, increased efficiency, and reduced wiring costs. Ad hoc networks, such as those enabled by Bluetooth, allow data synchronization with network systems and application sharing between devices. Bluetooth functionality also eliminates cables for printer and other peripheral device connections. Handheld devices such as personal digital assistants (PDA) and cell phones allow remote users to synchronize personal databases and provide access to network services such as wireless e-mail, Web browsing, and Internet access. Moreover, these technologies can offer dramatic cost savings and new capabilities to diverse applications ranging from retail settings to manufacturing shop floors to first responders.
However, risks are inherent in any wireless technology. Some of these risks are similar to those of wired networks; some are exacerbated by wireless connectivity; some are new. Perhaps the most significant source of risks in wireless networks is that the technology’s underlying communications medium, the airwave, is open to intruders, making it the logical equivalent of an Ethernet port in the parking lot. The loss of confidentiality and integrity and the threat of denial of service (DoS) attacks are risks
typically associated with wireless communications. Unauthorized users may gain access to agency systems and information, corrupt the agency’s data, consume network bandwidth, degrade network performance, launch attacks that prevent authorized users from accessing the network, or use agency resources to launch attacks on other networks.
Specific threats and vulnerabilities to wireless networks and handheld devices include the following:
- All the vulnerabilities that exist in a conventional wired network apply to wireless technologies.
- Malicious entities may gain unauthorized access to an agency’s computer network through wireless connections, bypassing any firewall protections.
- Sensitive information that is not encrypted (or that is encrypted with poor cryptographic techniques) and that is transmitted between two wireless devices may be intercepted and disclosed.
- DoS attacks may be directed at wireless connections or devices.
- Malicious entities may steal the identity of legitimate users and masquerade as them on internal or external corporate networks.
- Sensitive data may be corrupted during improper synchronization.
- Malicious entities may be able to violate the privacy of legitimate users and be able to track their movements.
- Malicious entities may deploy unauthorized equipment (e.g., client devices and access points) to surreptitiously gain access to sensitive information.
- Handheld devices are easily stolen and can reveal sensitive information.
- Data may be extracted without detection from improperly configured devices.
- Viruses or other malicious code may corrupt data on a wireless device and subsequently be introduced to a wired network connection.
- Malicious entities may, through wireless connections, connect to other agencies or organizations for the purposes of launching attacks and concealing their activities.
- Interlopers, from inside or out, may be able to gain connectivity to network management controls and thereby disable or disrupt operations.
- Malicious entities may use third-party, untrusted wireless network services to gain access to an agency’s or other organization’s network resources.
- Internal attacks may be possible via ad hoc transmissions.
Agencies should be aware that maintaining a secure wireless network is an ongoing process that requires greater effort than that required for other networks and systems. Moreover, it is important that agencies assess risks more frequently and test and evaluate system security controls when wireless technologies are deployed.
Maintaining a secure wireless network and associated devices requires significant effort, resources, and vigilance and involves the following steps:
Maintaining a full understanding of the topology of the wireless network.
Labeling and keeping inventories of the fielded wireless and handheld devices.
Creating backups of data frequently.
Performing periodic security testing and assessment of the wireless network.
Performing ongoing, randomly timed security audits to monitor and track wireless and handheld devices.
Applying patches and security enhancements.
Monitoring the wireless industry for changes to standards that enhance security features and for the release of new products.
Vigilantly monitoring wireless technology for new threats and vulnerabilities.
Agencies should not undertake wireless deployment for essential operations until they have examined and can acceptably manage and mitigate the risks to their information, system operations, and continuity of essential operations. Agencies should perform a risk assessment and develop a security policy before purchasing wireless technologies, because their unique security requirements will determine which products should be considered for purchase.