Air Broadband

Explain the ABCs of IEEE 802.11
What can you do with WLAN?
What channels are available in IEEE 802.11b/g?
What channels are available in IEEE 802.11a?
Why is WLAN AP coverage so small?
How is the optimum cell design achieved?
What is WLAN switch?
Is there a more formal definition of WLAN switch?
What is Air Broadband's Soft-Roaming™?
What other technologies can achieve layer-3 roaming?
What is Air Broadband's wireless aware switching?
What is the market potential for WLAN/WMAN technology?
What are the differences between IEEE 802.11, 802.15, 802.16 and 802.20?
How does PoE (inline power or IEEE 802.3af) work in a WLAN environment?
Can you compare WLAN with other technologies?

Q. Explain the ABCs of IEEE 802.11.

A. In addition to 802.11a/b/g, there are several other standards under 802.11:

802.11a A physical layer standard/ 5GHz radio band/ eight radio channels (12 channels in some countries). Maximum link rate of 54-Mbps per channel. Completed in 1999.

802.11b A physical layer standard/ 2.4GHz radio band/ 3 available radio channels. Maximum link rate of 11-Mbps per channel. Completed in 1999.

802.11d Supplementary to the Media Access Control (MAC) layer- allow the permissible radio channels with acceptable power levels to operate within the rules of these countries. Work is ongoing.

802.11e Supplementary to the MAC layer to provide QoS support- provide classes of service with managed levels of QoS for data, voice and video applications.

802.11f This is a "recommended practice" document to achieve radio AP interoperability when a user is handed over from one access point to another from multi-vender.

802.11g A physical layer standard in the 2.4GHz and 5GHz radio band- three available radio channels/ 54-Mbps per channel/ orthogonal frequency-division multiplexing (OFDM) modulation/ complementary code keying (CCK) modulation for backward compatibility with 11b and, packet binary convolutional coding (PBCC) modulation as an option for faster link rates. Modulation issues.

802.11h Supplementary to the MAC layer- to comply with European regulations for 5GHz WLANs- transmission power control (TPC) and dynamic frequency selection (DFS). Alternative is HyperLAN standard defined by ETSI. Expected by the H2 of 2002.

802.11i Supplementary to the MAC layer- to improve security beyond Wired Equivalent Privacy (WEP) with new encryption methods and authentication procedures. IEEE 802.1x forms a key part of 802.11i. Start with firmware upgrades using the Temporal Key Integrity Protocol (TKIP), followed by new silicon with AES (an iterated block cipher) and TKIP backwards compatibility.

802.11k Creates a way for access points to pass specific radio frequency health and management data to higher-level management applications.

802.11n Designed to boost throughput, not raw data rate, to 100M bit/sec. The idea is to make WLANs feel like 100M bit/sec switched Ethernet LANs.

Q. What can you do with WLAN?

A. You can run all existing applications (since WLAN is an extension to LAN), plus the applications that require mobility.

?General Application: High Speed Wireless Internet

?Vertical Application: Hospital, warehouse, factory, university, hotel, museum, stadium, etc.

?Hot-spot Application: Airport, coffee shop, restaurant, etc.

?Killer Applications: Wireless Video Surveillance & VoWLAN

?Value Add Application: Location Based Services

Q. What channels are available in IEEE 802.11b/g?

A.?There are 11 22-MHz-wide channels; 14 internationally.

Q. What channels are available in IEEE 802.11a?

A.?There are 8 20-MHz-wide channels; more internationally.

Q. Why is WLAN AP coverage so small?

A. The radio transmission power level is limited since WLAN uses ISM band as follows:

?IEEE 802.11b

IEEE 802.11a

Q. How is the optimum cell design achieved?

A. There are three non-overlapping channels available in 802.11b.?The ideal reuse of those non-overlapping channels, i.e. CH1, 6 and 11, is shown below.?Four less overlapped channels, i.e. CH 1, 4, 8 and 11, can be used if needed which does cause some level of interference.?Similar guidelines can be used for 802.11a; 11a has 8 non-overlapping channels.

Q. What is WLAN switch?

A. WLAN switch resides on the wired portion of the network between the 802.11 AP and the protected side of LAN, providing scalable security, management, roaming capabilities and other features.

The product was introduced due to the issues that WLAN AP alone could not resolve.

?Security is exposed: Biggest concern for both enterprise/public deployments

?Network management gets very difficult: APs and mobile user management add new challenges

?IP subnet boundaries break: User moves from one subnet to another with the same IP address

?Real-time traffic increases: VoIP and streaming video applications became popular

?Subnet capacity requirement increases: Mobile users put extra load in particular subnets

Q. Is there a more formal definition of WLAN switch?

A. As this class of product is still in its infant stage, the definition of WLAN switch is still being disputed.?However, here is our definition:

1. Layer 2/3 Subnet Roaming: In order to support roaming from one network to another, wireless switches provide subnet roaming that allows users to roam without needing to re-authenticate with the system.

2. User Authentication - Wireless switches have own database for authenticating users; however, some offer external interfaces to authentication servers such as RADIUS and LDAP.

3. Cryptography: Provide encryption of data from the client to the network and back, using such security as IPSec and PPTP encrypted VPN tunnels.

4. Centralized Management: Enables the access points to have fewer functions, reducing the need to interface with the access points when performing configuration and other support tasks.

5. Integration with Wired IP infrastructure: Ease of integration with the existing wired IP infrastructure is a must for any wireless networking equipment including the wireless switch.

6. Wireless Traffic Awareness: Identifying and handling of wireless traffic in order to maximize the benefits such as mobility, while minimizing the shortfalls.

7. Multimedia Support: The very nature of mobility provided by WLAN makes it a perfect media to carry multimedia data such as voice and streaming video.

8. Provisioning capability: Provide bandwidth management through the assignment of user profiles based on provisioned quality of service levels and throughput limit at user level

9. Carrier Class Readiness: The ultimate customer for the WLAN technology will be the public. The reasonable expectation is that 50% of the Internet traffic to be wireless in next 3-4 years. Wireless switches will soon have to face public access deployment by carrier.

Q. What is Air Broadband’s Soft-Roaming?

A. Soft-Roaming?is our patent pending layer-2/3 roaming technology that provides seamless, always-on and real-time connectivity for true mobility.

Q. What other technologies can achieve layer-3 roaming?

A. There are two other known technologies that can provide layer-3 roaming.

Mobile IP: Failed to gain popularity in the U.S. market due to several weaknesses

- Unpredictable latency (not delay sensitive)

- Requires at least two precious IP addresses per user

- Requires Mobile IP client software on each mobile device

? ?- Requires compatibility between all foreign agent/home agent (FA/HA)

VLAN: ?/span>Can create virtual layer-2 space over physical layer-3 space

- Rely on legacy infrastructure for roaming (not delay sensitive)

- Not scalable for large size deployment

- Cumbersome to add/delete users (configuration issue)

- Wrong configuration creates a security hole to the entire system

- All legacy equipment in the pipe needs to support VLAN

Q. What is Air Broadband’s wireless aware switching?

A. Airobatics WLAN switch differs from the traditional wired switch and other WLAN switches because it switches traffic based on:

1. True mobility- Soft-Roaming,

2. AP throughput optimization,

3. Tracking user location,

4. Intelligent resource sharing and

5. Heavy users, not heavy bandwidth as in wired LAN

Q. What is the market potential for WLAN/WMAN technology?

A. IEEE 802.11/16 is the only broadband wireless that can truly be called standard.?As the 2G/3G cellular technology created a huge market segment in the industry, we believe in a much bigger deployment of WLAN/WMAN and we see the following:

- Silicon valley will become one big hotspot as with many other major cities,

- 50% of all Internet traffic will come from WLAN/WMAN users by 2008 and

- The very nature of WLAN will finally make multimedia applications (VoIP and streaming video) more appealing to users.

Q. What are the differences between IEEE 802.11, 802.15, 802.16 and 802.20?

A. As we’ve seen with IEEE 802.3, WLAN (802.11) and its sister technologies can bring a significant progress in networking; this time for a wireless enabled world.

?IEEE 802.11: ?Wireless LAN (Local Area Networks), Wi-Fi

?IEEE 802.15: ?Wireless PAN (Personal Area Networks), similar to Bluetooth

?IEEE 802.16: ?Wireless MAN (Metropolitan Area Networks), Wi-Max

?Point-to-multipoint line-of-site in the 10-66 GHz range up to 120Mbps

IEEE 802.16a: ?Operates in the licensed and unlicensed frequencies between 2GHz and 11GHz non-line-of-site using OFDM, similar to 802.11a/g

?IEEE 802.16e: ?Based on 802.16a, add mobility in the 2 to 6 GHz licensed bands

?IEEE 802.20: ?Vehicular Mobility, aims for operation in licensed bands below 3.5GHz.

Q. How does PoE (Inline Power or IEEE 802.3af) work in a WLAN environment?

A. It depends on the switch and APs used. Three possible configurations can be achieved:?

?/span>

Q. Can you compare WLAN with other technologies?

A. Please refer to the chart below showing different technologies relative to speed and mobility.




Company Jobs Contact Resources Q & A	Q & A Explain the ABCs of IEEE 802.11 What can you do with WLAN? What channels are available in IEEE 802.11b/g? What channels are available in IEEE 802.11a? Why is WLAN AP coverage so small? How is the optimum cell design achieved? What is WLAN switch? Is there a more formal definition of WLAN switch? What is Air Broadband's Soft-Roaming™? What other technologies can achieve layer-3 roaming? What is Air Broadband's wireless aware switching? What is the market potential for WLAN/WMAN technology? What are the differences between IEEE 802.11, 802.15, 802.16 and 802.20? How does PoE (inline power or IEEE 802.3af) work in a WLAN environment? Can you compare WLAN with other technologies? Q. Explain the ABCs of IEEE 802.11. A. In addition to 802.11a/b/g, there are several other standards under 802.11: 802.11a A physical layer standard/ 5GHz radio band/ eight radio channels (12 channels in some countries). Maximum link rate of 54-Mbps per channel. Completed in 1999. 802.11b A physical layer standard/ 2.4GHz radio band/ 3 available radio channels. Maximum link rate of 11-Mbps per channel. Completed in 1999. 802.11d Supplementary to the Media Access Control (MAC) layer- allow the permissible radio channels with acceptable power levels to operate within the rules of these countries. Work is ongoing. 802.11e Supplementary to the MAC layer to provide QoS support- provide classes of service with managed levels of QoS for data, voice and video applications. 802.11f This is a "recommended practice" document to achieve radio AP interoperability when a user is handed over from one access point to another from multi-vender. 802.11g A physical layer standard in the 2.4GHz and 5GHz radio band- three available radio channels/ 54-Mbps per channel/ orthogonal frequency-division multiplexing (OFDM) modulation/ complementary code keying (CCK) modulation for backward compatibility with 11b and, packet binary convolutional coding (PBCC) modulation as an option for faster link rates. Modulation issues. 802.11h Supplementary to the MAC layer- to comply with European regulations for 5GHz WLANs- transmission power control (TPC) and dynamic frequency selection (DFS). Alternative is HyperLAN standard defined by ETSI. Expected by the H2 of 2002. 802.11i Supplementary to the MAC layer- to improve security beyond Wired Equivalent Privacy (WEP) with new encryption methods and authentication procedures. IEEE 802.1x forms a key part of 802.11i. Start with firmware upgrades using the Temporal Key Integrity Protocol (TKIP), followed by new silicon with AES (an iterated block cipher) and TKIP backwards compatibility. 802.11k Creates a way for access points to pass specific radio frequency health and management data to higher-level management applications. 802.11n Designed to boost throughput, not raw data rate, to 100M bit/sec. The idea is to make WLANs feel like 100M bit/sec switched Ethernet LANs. Q. What can you do with WLAN? A. You can run all existing applications (since WLAN is an extension to LAN), plus the applications that require mobility. ?General Application: High Speed Wireless Internet ?Vertical Application: Hospital, warehouse, factory, university, hotel, museum, stadium, etc. ?Hot-spot Application: Airport, coffee shop, restaurant, etc. ?Killer Applications: Wireless Video Surveillance & VoWLAN ?Value Add Application: Location Based Services Q. What channels are available in IEEE 802.11b/g? A.?There are 11 22-MHz-wide channels; 14 internationally. Q. What channels are available in IEEE 802.11a? A.?There are 8 20-MHz-wide channels; more internationally. Q. Why is WLAN AP coverage so small? A. The radio transmission power level is limited since WLAN uses ISM band as follows: ?IEEE 802.11b IEEE 802.11a Q. How is the optimum cell design achieved? A. There are three non-overlapping channels available in 802.11b.?The ideal reuse of those non-overlapping channels, i.e. CH1, 6 and 11, is shown below.?Four less overlapped channels, i.e. CH 1, 4, 8 and 11, can be used if needed which does cause some level of interference.?Similar guidelines can be used for 802.11a; 11a has 8 non-overlapping channels. Q. What is WLAN switch? A. WLAN switch resides on the wired portion of the network between the 802.11 AP and the protected side of LAN, providing scalable security, management, roaming capabilities and other features. The product was introduced due to the issues that WLAN AP alone could not resolve. ?Security is exposed: Biggest concern for both enterprise/public deployments ?Network management gets very difficult: APs and mobile user management add new challenges ?IP subnet boundaries break: User moves from one subnet to another with the same IP address ?Real-time traffic increases: VoIP and streaming video applications became popular ?Subnet capacity requirement increases: Mobile users put extra load in particular subnets Q. Is there a more formal definition of WLAN switch? A. As this class of product is still in its infant stage, the definition of WLAN switch is still being disputed.?However, here is our definition: 1. Layer 2/3 Subnet Roaming: In order to support roaming from one network to another, wireless switches provide subnet roaming that allows users to roam without needing to re-authenticate with the system. 2. User Authentication - Wireless switches have own database for authenticating users; however, some offer external interfaces to authentication servers such as RADIUS and LDAP. 3. Cryptography: Provide encryption of data from the client to the network and back, using such security as IPSec and PPTP encrypted VPN tunnels. 4. Centralized Management: Enables the access points to have fewer functions, reducing the need to interface with the access points when performing configuration and other support tasks. 5. Integration with Wired IP infrastructure: Ease of integration with the existing wired IP infrastructure is a must for any wireless networking equipment including the wireless switch. 6. Wireless Traffic Awareness: Identifying and handling of wireless traffic in order to maximize the benefits such as mobility, while minimizing the shortfalls. 7. Multimedia Support: The very nature of mobility provided by WLAN makes it a perfect media to carry multimedia data such as voice and streaming video. 8. Provisioning capability: Provide bandwidth management through the assignment of user profiles based on provisioned quality of service levels and throughput limit at user level *9. Carrier Class Readiness:* The ultimate customer for the WLAN technology will be the public. The reasonable expectation is that 50% of the Internet traffic to be wireless in next 3-4 years. Wireless switches will soon have to face public access deployment by carrier. Q. What is Air Broadband’s Soft-Roaming? A. Soft-Roaming?is our patent pending layer-2/3 roaming technology that provides seamless, always-on and real-time connectivity for true mobility. Q. What other technologies can achieve layer-3 roaming? A. There are two other known technologies that can provide layer-3 roaming. Mobile IP: Failed to gain popularity in the U.S. market due to several weaknesses ? - Unpredictable latency (not delay sensitive) - Requires at least two precious IP addresses per user - Requires Mobile IP client software on each mobile device ? ?- Requires compatibility between all foreign agent/home agent (FA/HA) VLAN: ?/span>Can create virtual layer-2 space over physical layer-3 space ? - Rely on legacy infrastructure for roaming (not delay sensitive) - Not scalable for large size deployment - Cumbersome to add/delete users (configuration issue) - - Wrong configuration creates a security hole to the entire system - All legacy equipment in the pipe needs to support VLAN Q. What is Air Broadband’s wireless aware switching? A. Airobatics WLAN switch differs from the traditional wired switch and other WLAN switches because it switches traffic based on: 1. True mobility- Soft-Roaming, 2. AP throughput optimization, 3. Tracking user location, 4. Intelligent resource sharing and 5. Heavy users, not heavy bandwidth as in wired LAN Q. What is the market potential for WLAN/WMAN technology? A. IEEE 802.11/16 is the only broadband wireless that can truly be called standard.?As the 2G/3G cellular technology created a huge market segment in the industry, we believe in a much bigger deployment of WLAN/WMAN and we see the following: - Silicon valley will become one big hotspot as with many other major cities, - 50% of all Internet traffic will come from WLAN/WMAN users by 2008 and - The very nature of WLAN will finally make multimedia applications (VoIP and streaming video) more appealing to users. Q. What are the differences between IEEE 802.11, 802.15, 802.16 and 802.20? A. As we’ve seen with IEEE 802.3, WLAN (802.11) and its sister technologies can bring a significant progress in networking; this time for a wireless enabled world. ?IEEE 802.11: ?Wireless LAN (Local Area Networks), Wi-Fi ?IEEE 802.15: ?Wireless PAN (Personal Area Networks), similar to Bluetooth ?IEEE 802.16: ?Wireless MAN (Metropolitan Area Networks), Wi-Max ?Point-to-multipoint line-of-site in the 10-66 GHz range up to 120Mbps IEEE 802.16a: ?Operates in the licensed and unlicensed frequencies between 2GHz and 11GHz non-line-of-site using OFDM, similar to 802.11a/g ?IEEE 802.16e: ?Based on 802.16a, add mobility in the 2 to 6 GHz licensed bands ?IEEE 802.20: ?Vehicular Mobility, aims for operation in licensed bands below 3.5GHz. Q. How does PoE (Inline Power or IEEE 802.3af) work in a WLAN environment? A. It depends on the switch and APs used. Three possible configurations can be achieved:? ?/span> Q. Can you compare WLAN with other technologies? A. Please refer to the chart below showing different technologies relative to speed and mobility.
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