Wi-Fi in the sky. Satellite Broadband Internet and TV service.
12.24.2009
12.23.2009
Day of reckoning for startups, consolidation of network security appliances
VCs get out of the security game? "We're going to see some shakeups. It might very well be the year that a lot of venture capital firms try to recoup some of their investments," Kindervag said. "So you'll see a lot of VC-backed companies merging together or being bought by larger companies. I think a lot of [them] have run out of cash, and there's not much of an appetite to pour more money into some of these things."
Super network security devices: Kindervag said 2010 could bring a new generation of network security appliances that do -- well -- just about everything. "If there is any hot technology for next year, it will probably be security devices that are uber-intelligent and extremely fast – a cross between unified threat management and what some people are calling next-generation firewall architectures. These will be devices where a tremendous amount of intelligence is applied to the packet, all the way up to Layer 7, in near real time at any speed, whether it is a 10 Gb core or better. That's where everything is moving to – this consolidation of multiple technologies which will just be features on more robust security gateways. So you can turn on the firewall feature, you can turn on the IPS feature. They will all be embedded into this codebase and they will all be able to function within a single clock cycle.
VoIP and unified communications security awareness: Enterprises will play catch up with securing newly installed IP telephony and collaboration technologies that were deployed without a proper network security vetting, Kindervag said. "There's all this new stuff and we haven't implemented it securely. We've implemented it in an ad hoc way, and we need to secure it. This is something that hasn't happened before," he said. "It used to be you had to go through a long process to determine whether something is secure and then implement it. Now we're looking at whether it's secure long after it's been in general usage. Everything changed so quickly, with the rise of social networking and Web 2.0 that the demand from the user side was so great and it couldn't be controlled by a small group of 'paranoid' security types."
Super network security devices: Kindervag said 2010 could bring a new generation of network security appliances that do -- well -- just about everything. "If there is any hot technology for next year, it will probably be security devices that are uber-intelligent and extremely fast – a cross between unified threat management and what some people are calling next-generation firewall architectures. These will be devices where a tremendous amount of intelligence is applied to the packet, all the way up to Layer 7, in near real time at any speed, whether it is a 10 Gb core or better. That's where everything is moving to – this consolidation of multiple technologies which will just be features on more robust security gateways. So you can turn on the firewall feature, you can turn on the IPS feature. They will all be embedded into this codebase and they will all be able to function within a single clock cycle.
VoIP and unified communications security awareness: Enterprises will play catch up with securing newly installed IP telephony and collaboration technologies that were deployed without a proper network security vetting, Kindervag said. "There's all this new stuff and we haven't implemented it securely. We've implemented it in an ad hoc way, and we need to secure it. This is something that hasn't happened before," he said. "It used to be you had to go through a long process to determine whether something is secure and then implement it. Now we're looking at whether it's secure long after it's been in general usage. Everything changed so quickly, with the rise of social networking and Web 2.0 that the demand from the user side was so great and it couldn't be controlled by a small group of 'paranoid' security types."
Cisco-EMC-VMware, oh my! And more options for virtualization, automation, mobility, and video management
Cisco-EMC-VMware: Cisco's alliance with EMC and VMware to form the Virtual Computing Coalition, announced in November, signified "the next step of how Cisco is going to try to move into the computing marketplace more aggressively," Frey said. The coalition's products marked "the first time a complete turnkey modular solution has come from someone other than the major systems vendors," said Frey, who predicted that it would propel a simpler network management environment.
Virtualization management gets easier: Application-based vendors will continue to add support for and recognize more virtualized infrastructure, Frey said, lowering capital expenses and deployment times for enterprises. "Everything's going virtual," he said. "I know this is not new, but especially in the second half of next year … all the management tool [vendors will be] either adding support for virtual components … or recognizing virtual components."
Mobility: Wireless LAN is here to stay, and not all enterprises are prepared. "There's no slowing the pace of growth in the use of mobile endpoints, and a number of times they're showing up as the preferred end client." "The challenge around this is the more and more people want to use those as their primary computing device, you've got a whole new set of challenges for measuring and [securing] the user experience."
Video on the network: Cisco's acquisition of Tandberg will translate into "a lot more aggressive deployment of video conferencing," Frey said. "Cisco does this for a reason -- it requires a lot bigger network. You need more bandwidth." Many enterprises have yet to embrace video conferencing and won't have their networks prepared for the rush, he added. "It will be sort of like voice over IP in its first years of existence." . "Once they started to roll [VoIP] out over their entire organizations, they realized how many skeletons they had in the proverbial wiring closet." If enterprises aren't prepared, he said, they can expect 10 times the wiring challenges they faced with VoIP.
Virtualization management gets easier: Application-based vendors will continue to add support for and recognize more virtualized infrastructure, Frey said, lowering capital expenses and deployment times for enterprises. "Everything's going virtual," he said. "I know this is not new, but especially in the second half of next year … all the management tool [vendors will be] either adding support for virtual components … or recognizing virtual components."
Mobility: Wireless LAN is here to stay, and not all enterprises are prepared. "There's no slowing the pace of growth in the use of mobile endpoints, and a number of times they're showing up as the preferred end client." "The challenge around this is the more and more people want to use those as their primary computing device, you've got a whole new set of challenges for measuring and [securing] the user experience."
Video on the network: Cisco's acquisition of Tandberg will translate into "a lot more aggressive deployment of video conferencing," Frey said. "Cisco does this for a reason -- it requires a lot bigger network. You need more bandwidth." Many enterprises have yet to embrace video conferencing and won't have their networks prepared for the rush, he added. "It will be sort of like voice over IP in its first years of existence." . "Once they started to roll [VoIP] out over their entire organizations, they realized how many skeletons they had in the proverbial wiring closet." If enterprises aren't prepared, he said, they can expect 10 times the wiring challenges they faced with VoIP.
HP-3Com affects prices, rise of the two-tiered data center network
HP-3Com shakeup will drive down prices: The merger between HP and 3Com will push up HP ProCurve far enough to be nipping at Cisco's heels, with Juniper Networks picking up the rear. "We'll now have a market where there are a number of large viable competitors." "We're going to see a lot more competition, and for folks who do a good job doing competitive sourcing with pricing, they will save a lot of money."
From three to two: "We will see networks evolve," Skorupa said. "Today, typically they're built in three tiers -- core, aggregate and edge -- and the new networks being built will collapse." In an effort to simplify network management, ease troubleshooting and lower costs, networks will fall back to two tiers.
From three to two: "We will see networks evolve," Skorupa said. "Today, typically they're built in three tiers -- core, aggregate and edge -- and the new networks being built will collapse." In an effort to simplify network management, ease troubleshooting and lower costs, networks will fall back to two tiers.
Wireless LAN predictions: Cheaper access points, more robust and reliable networks
802.11n prices will drop: "We saw a beginning to that in 2009 with Aruba, Aerohive and Meraki all having a little more pricing competition," DeBeasi said. "We're going to continue to see that. And the silicon vendors, their next-generation silicon will be lower power, lower cost."
WLAN vendors strive to make wireless more robust, reliable: Every vendor will continue to introduce techniques aimed at making wireless networks more reliable and robust, DeBeasi said. "The throughput [of 802.11n] is better, but can [enterprises] depend on it? There are lots of techniques that vendors are adding." Current techniques from vendors include beamforming, airtime fairness and bandwidth steering. "We're going to see improvements in beamforming [and other techniques] in 2010," he said.
Expect 1x1 MIMO, 4x4 MIMO and everything between: DeBeasi said most of the 802.11n products on the market so far have utilized 3x3 or 2x3 MIMO (multiple input, multiple output). He expects vendors to offer a full range of receiver and transmitter arrays in 2010. "I think we'll see some 1x1 products, lower-power and lower-cost products. The throughput will be lower, too, of course. I think the iPhone might come out with a 1x1 802.11n capability this year. And at the high end, we'll probably begin to see, near the end of the year, 4x4 MIMO in enterprise access points to offer better throughput."
WLAN vendors strive to make wireless more robust, reliable: Every vendor will continue to introduce techniques aimed at making wireless networks more reliable and robust, DeBeasi said. "The throughput [of 802.11n] is better, but can [enterprises] depend on it? There are lots of techniques that vendors are adding." Current techniques from vendors include beamforming, airtime fairness and bandwidth steering. "We're going to see improvements in beamforming [and other techniques] in 2010," he said.
Expect 1x1 MIMO, 4x4 MIMO and everything between: DeBeasi said most of the 802.11n products on the market so far have utilized 3x3 or 2x3 MIMO (multiple input, multiple output). He expects vendors to offer a full range of receiver and transmitter arrays in 2010. "I think we'll see some 1x1 products, lower-power and lower-cost products. The throughput will be lower, too, of course. I think the iPhone might come out with a 1x1 802.11n capability this year. And at the high end, we'll probably begin to see, near the end of the year, 4x4 MIMO in enterprise access points to offer better throughput."
OSI Reference Model
Layer 7: The application layer ...This is the layer at which communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the application itself, although some applications may perform application layer functions.)
Layer 6: The presentation layer ...This is a layer, usually part of an operating system, that converts incoming and outgoing data from one presentation format to another (for example, from a text stream into a popup window with the newly arrived text). Sometimes called the syntax layer.
Layer 5: The session layer ...This layer sets up, coordinates, and terminates conversations, exchanges, and dialogs between the applications at each end. It deals with session and connection coordination.
Layer 4: The transport layer ...This layer manages the end-to-end control (for example, determining whether all packets have arrived) and error-checking. It ensures complete data transfer.
Layer 3: The network layer ...This layer handles the routing of the data (sending it in the right direction to the right destination on outgoing transmissions and receiving incoming transmissions at the packet level). The network layer does routing and forwarding.
Layer 2: The data-link layer ...This layer provides synchronization for the physical level and does bit-stuffing for strings of 1's in excess of 5. It furnishes transmission protocol knowledge and management.
Layer 1: The physical layer ...This layer conveys the bit stream through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier.
Open Systems Interconnection ( OSI ) is a standard reference model for communication between two end users in a network. The model is used in developing products and understanding networks.
The Data-Link Layer | OSI
Layer 2 refers to the Data Link layer of the commonly-referenced multilayered communication model, Open Systems Interconnection (OSI). The Data Link layer is concerned with moving data across the physical links in the network. In a network, the switch is a device that redirects data messages at the layer 2 level, using the destination Media Access Control (MAC) address to determine where to direct the message.
The Data-Link layer contains two sublayers that are described in the IEEE-802 LAN standards:
* Media Access Control (MAC) sublayer
* Logical Link Control (LLC) sublayer
The Data Link layer ensures that an initial connection has been set up, divides output data into data frames, and handles the acknowledgements from a receiver that the data arrived successfully. It also ensures that incoming data has been received successfully by analyzing bit patterns at special places in the frames.The OSI seven-layer model – What is a layer?
* The Application Layer (Layer 7)
* The Presentation Layer (Layer 6)
* The Session Layer (Layer 5)
* The Transport Layer (Layer 4)
* The Network Layer (Layer 3)
* The Data Link Layer (Layer 2)
* The Physical Layer (Layer 1)
* Putting all the layers together
The Data-Link layer contains two sublayers that are described in the IEEE-802 LAN standards:
* Media Access Control (MAC) sublayer
* Logical Link Control (LLC) sublayer
The Data Link layer ensures that an initial connection has been set up, divides output data into data frames, and handles the acknowledgements from a receiver that the data arrived successfully. It also ensures that incoming data has been received successfully by analyzing bit patterns at special places in the frames.The OSI seven-layer model – What is a layer?
* The Application Layer (Layer 7)
* The Presentation Layer (Layer 6)
* The Session Layer (Layer 5)
* The Transport Layer (Layer 4)
* The Network Layer (Layer 3)
* The Data Link Layer (Layer 2)
* The Physical Layer (Layer 1)
* Putting all the layers together
40 Gigabit Ethernet data center switches, a Layer 2 comeback
40 Gigabit Ethernet in the data center: Virtualization will drive innovation in the data center, and vendors will offer enterprise customers 40 Gigabit Ethernet. "[Virtualization] really hasn't impacted the network yet, but it's starting to," Kerravala said. "It'll push along 10 [Gigabit Ethernet adoption] and I think we'll see 40 [Gigabit Ethernet] products next year."
Diving back into Layer 2: Most enterprises are using native Ethernet, but Kerravala said virtualization will spur a return to TCP/IP. "From a virtualization standpoint, it's faster to do things at Layer 2," he said. "I think you'll see vendors spend a lot of time marketing TCP/IP as the primary protocol…. In some ways, it's 'Back to the Future.'"
WAN optimization: Layers 4 through 7 will also gain continued attention for wide-area network optimization products, Kerravala said, with F5 Networks and Riverbed as the market leaders. "The more reliant companies become on their network," he said, "the more important it is the networks be able to handle the different types of applications."
Diving back into Layer 2: Most enterprises are using native Ethernet, but Kerravala said virtualization will spur a return to TCP/IP. "From a virtualization standpoint, it's faster to do things at Layer 2," he said. "I think you'll see vendors spend a lot of time marketing TCP/IP as the primary protocol…. In some ways, it's 'Back to the Future.'"
WAN optimization: Layers 4 through 7 will also gain continued attention for wide-area network optimization products, Kerravala said, with F5 Networks and Riverbed as the market leaders. "The more reliant companies become on their network," he said, "the more important it is the networks be able to handle the different types of applications."
12.22.2009
Channel Planning with 802.11n and DFS
This video covers the challenges of channel bonding and whether DFS (Dynamic Frequency Selection) channels should be used.
Kubuntu
What is Kubuntu?
Kubuntu is a free, user-friendly operating system based on the KDE Software Compilation and on the award winning Ubuntu operating system. With a biannual release cycle and at least 18 months of free security updates for each release, it is the secure, stable computing environment you've been waiting for.
Take the tour or hear what our users have to say.There are now three ways for you to get Ubuntu. Just choose the delivery option that works best for you:
 | Download now - Download the Ubuntu, Edubuntu or Kubuntu CD installer to your computer now. Please note: the CD Installer is nearly 700M. If you don't have a fast internet connection you may want to consider requesting a CD. |
 | Buy on CD or DVD - Buy a CD or DVD with Ubuntu, Edubuntu or Kubuntu, or a large number of CDs from a distributor near you. If you are in North America you can get Ubuntu and Kubuntu on DVD from Amazon.com. |
 | Request a free CD- Request a free Ubuntu, Edubuntu or Kubuntu CD from Canonical.
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Sony Blu-ray Disc Wi-Fi enabled model
The Sony BDP-S560 not only delivers terrific high-definition images, but also excels at upconverting DVDs, too. And it does so in a Wi-Fi enabled model. But this model ($300, as of December 14, 2009) lacks the streaming media extras that competing Blu-ray Disc players offer.
The BDP-S560 was most impressive in our black-and-white Good Night and Good Luck test. Even water glasses sitting on a banquet table popped with clarity and brilliance. It did almost as well in color movies, with a nice feel of dimensionality in the Mission: Impossible III test. Only in the animated Cars did it disappoint, where a sense of flatness earned it a rating of only Good.
The player earned ratings of Very Goods down the line in our two DVD tests. In the Return of the King test, the colors looked less saturated than those from the reference Sony PlayStation 3 player, but more pleasing and realistic.
The BDP-S560 was most impressive in our black-and-white Good Night and Good Luck test. Even water glasses sitting on a banquet table popped with clarity and brilliance. It did almost as well in color movies, with a nice feel of dimensionality in the Mission: Impossible III test. Only in the animated Cars did it disappoint, where a sense of flatness earned it a rating of only Good.
The player earned ratings of Very Goods down the line in our two DVD tests. In the Return of the King test, the colors looked less saturated than those from the reference Sony PlayStation 3 player, but more pleasing and realistic.
802.11n Technology
Driven by 802.11n Technology, Worldwide Wireless LAN Semiconductor Market Will Experience Double-Digit Growth Through 2012, IDC Predicts
The worldwide wireless LAN (WLAN) semiconductor market is expected to pass the $4 billion mark by 2012 with a compound annual growth rate (CAGR) of 22.8%. While PCs will remain the largest application segment for WLAN semiconductors, mobile phone applications will grow at a CAGR of 49.3% and become the second-largest category for WLAN semiconductor revenue by 2012. IDC expects the MIMO-enhanced 802.11n technology to be the next growth driver for this market as the higher throughput and range provide a great opportunity for new applications and usage models.
"The need for connectivity and connected mobile clients continues to fuel the WLAN semiconductor market," said Ajit Deosthali, research manager for Short Range Wireless Semiconductors at IDC. "WLAN adoption is set to grow beyond notebook PC and into the mobile phone and consumer electronics devices."
Among other key findings are the following:
* WiFi is set to take off in mobile handsets with dual-mode phones that provide both conventional cellular and WLAN connectivity
* Connectivity is the fastest-growing segment for semiconductor companies, with WLAN leading the way. Mobile handsets and mobile internet devices will lead integration of WiFi radio with other radio technologies such as Bluetooth, FM, and GPS for personal area networks.
The worldwide wireless LAN (WLAN) semiconductor market is expected to pass the $4 billion mark by 2012 with a compound annual growth rate (CAGR) of 22.8%. While PCs will remain the largest application segment for WLAN semiconductors, mobile phone applications will grow at a CAGR of 49.3% and become the second-largest category for WLAN semiconductor revenue by 2012. IDC expects the MIMO-enhanced 802.11n technology to be the next growth driver for this market as the higher throughput and range provide a great opportunity for new applications and usage models.
"The need for connectivity and connected mobile clients continues to fuel the WLAN semiconductor market," said Ajit Deosthali, research manager for Short Range Wireless Semiconductors at IDC. "WLAN adoption is set to grow beyond notebook PC and into the mobile phone and consumer electronics devices."
Among other key findings are the following:
* WiFi is set to take off in mobile handsets with dual-mode phones that provide both conventional cellular and WLAN connectivity
* Connectivity is the fastest-growing segment for semiconductor companies, with WLAN leading the way. Mobile handsets and mobile internet devices will lead integration of WiFi radio with other radio technologies such as Bluetooth, FM, and GPS for personal area networks.
12.20.2009
The Fine Points of Optional Wi-Fi 802.11n Certification
The Wi-Fi Alliance explains four optional 802.11n elements for future certification: The Wi-Fi trade group has over the last 10 years kept together the notion that every device with Wi-Fi on the label should work at the greatest point of agreement with one another. This has continued in spite of new elements and enhancements to the 802.11 family of standards, including 802.11n.
The recent news that the IEEE had approved 802.11n within the 802.11 Working Group, and ratification was likely a few months away, led the Wi-Fi Alliance to explain its roadmap for adding more steps to the certification process. When the Wi-Fi group certifies a device, it runs it through tests that are supposed to ensure that the equipment responds in a standard manner. (The group also does plugfests in which equipment makers bring lots of gear together outside of lab conditions.)
When the word hit, the alliance identified four optional areas of certification that it would add. I knew about some of these areas, but I spoke with the group today to clarify what this meant for both equipment makers and end users. The Wi-Fi Alliance said it would offer tests for coexistence in 2.4 GHz, space-time block coding, transmit MPDU, and three spatial streams. Scratching your head? After 8 years of covering Wi-Fi, I admit I was in that position over a couple of those.
Coexistence has to do with the use of double-wide channels--40 MHz instead of the roughly 20 MHz regular channels--in both 2.4 and 5 GHz bands.
The 5 GHz band isn't a problem, because 20 MHz channels don't overlap; Wi-Fi selectable channels in 5 GHz are staggered by intervals of 4 band channels (5 MHz each), such as 36, 40, 44, and 48. In 2.4 GHz, channels are staggered only by a single 5 MHz band channel, meaning that the use of 40 MHz will nearly always conflict with other existing networks.
Ennis said that 2.4 GHz coexistence terms weren't fully settled until recently, even though manufacturers have built in some methods of using 40 MHz in 2.4 GHz. The Wi-Fi Alliance discouarged the use; Apple, for one, doesn't allow its gear to use wide channels in 2.4 GHz.
In the new testing regime, "not everybody is required to support 40 MHz operation--but if they do support 40 MHz operation, they must go through the testing that we've defined," Ennis said.
The mechanisms that require an access point backing off to 20 MHz channels are so broad and severe that it's unlikely you could use a wide channel in any environment in which other Wi-Fi networks operate. Still, Ennis says, it may be of use in enteprise situations, or with future gear that's all 802.11n with these modes enabled that can be more respectful of each other automatically.
Space-time block coding. This term makes my head hurt every time I read it. I go off to the Web and read up on the principle, and it's above my paygrade. All wireless communication has to allot slots in some fashion--through contention or scheduling--for bits to go through. That's the basis of all wireless standards.
What STBC does is extend that beyond time into the domain of space. An access point can, through some complicated encoding, send different information simultaneously using multiple spatial streams so that receivers (stations in Wi-Fi parlance) that have single-spatial stream receivers can separately but at the same time decode their unique package.
The utility of this complicated feature is that we're likely to start seeing lots of single-stream N devices.
Chipmakers are most likely now delivering quantities of these lower-powered, cheaper 802.11n chips that can't offer two streams--and thus double the bandwidth--as laptop and desktop 802.11n modules can. With STBC, an access point can utilize the full available 802.11n bandwidth by splitting it spatially between two devices instead of halving bandwidth by speaking to a single-stream device solely.
Ennis noted that STBC also improves the signal-to-noise ratio, which makes faster rates and farther distances possible. "I think this is going to be a popular optional feature," he said.
Aggregation MPDUs (MAC Protocol Data Units). While sounding obscure, this is yet another way by which 802.11n can eke out improved speeds. For long sequences of data, aggregation MPDUs lets a Wi-Fi system create a long frame, reducing all the overhead required to send a packet. (Every packet has origin and destination information, a preamble, and other data that adds overhead.)
For video, for instance, Ennis says that this kind of aggregation can improve throughput, although probably not by double-digit percentages. "It's not as dramatic an improvement as say using more spatial streams, or using 40 MHz channels," he said.
Currently, the Wi-Fi Alliance tests aggregation only if a manufacturer's access point sends these aggregated frames; it checks that a station can properly receive such frames, which can be interpreted under earlier 802.11n drafts. The new optional certification tests for aggregated frames sent by both stations and access points. (If included, it must be tested.)
Three spatial streams. This last one is quite simple. The Wi-Fi Alliance can now test for devices that send three streams of data across space up from two streams of data. Ultimately, we should see devices that can handle four, with a maximum raw symbol rate of 600 Mbps with wide channels in 5 GHz.
Those are the technical bits. The a/b/g/draft n labeling can only go so far and there should be more news on that front soon.
The recent news that the IEEE had approved 802.11n within the 802.11 Working Group, and ratification was likely a few months away, led the Wi-Fi Alliance to explain its roadmap for adding more steps to the certification process. When the Wi-Fi group certifies a device, it runs it through tests that are supposed to ensure that the equipment responds in a standard manner. (The group also does plugfests in which equipment makers bring lots of gear together outside of lab conditions.)
When the word hit, the alliance identified four optional areas of certification that it would add. I knew about some of these areas, but I spoke with the group today to clarify what this meant for both equipment makers and end users. The Wi-Fi Alliance said it would offer tests for coexistence in 2.4 GHz, space-time block coding, transmit MPDU, and three spatial streams. Scratching your head? After 8 years of covering Wi-Fi, I admit I was in that position over a couple of those.
Coexistence has to do with the use of double-wide channels--40 MHz instead of the roughly 20 MHz regular channels--in both 2.4 and 5 GHz bands.
The 5 GHz band isn't a problem, because 20 MHz channels don't overlap; Wi-Fi selectable channels in 5 GHz are staggered by intervals of 4 band channels (5 MHz each), such as 36, 40, 44, and 48. In 2.4 GHz, channels are staggered only by a single 5 MHz band channel, meaning that the use of 40 MHz will nearly always conflict with other existing networks.Ennis said that 2.4 GHz coexistence terms weren't fully settled until recently, even though manufacturers have built in some methods of using 40 MHz in 2.4 GHz. The Wi-Fi Alliance discouarged the use; Apple, for one, doesn't allow its gear to use wide channels in 2.4 GHz.
In the new testing regime, "not everybody is required to support 40 MHz operation--but if they do support 40 MHz operation, they must go through the testing that we've defined," Ennis said.
The mechanisms that require an access point backing off to 20 MHz channels are so broad and severe that it's unlikely you could use a wide channel in any environment in which other Wi-Fi networks operate. Still, Ennis says, it may be of use in enteprise situations, or with future gear that's all 802.11n with these modes enabled that can be more respectful of each other automatically.
Space-time block coding. This term makes my head hurt every time I read it. I go off to the Web and read up on the principle, and it's above my paygrade. All wireless communication has to allot slots in some fashion--through contention or scheduling--for bits to go through. That's the basis of all wireless standards.
What STBC does is extend that beyond time into the domain of space. An access point can, through some complicated encoding, send different information simultaneously using multiple spatial streams so that receivers (stations in Wi-Fi parlance) that have single-spatial stream receivers can separately but at the same time decode their unique package.
The utility of this complicated feature is that we're likely to start seeing lots of single-stream N devices.
Chipmakers are most likely now delivering quantities of these lower-powered, cheaper 802.11n chips that can't offer two streams--and thus double the bandwidth--as laptop and desktop 802.11n modules can. With STBC, an access point can utilize the full available 802.11n bandwidth by splitting it spatially between two devices instead of halving bandwidth by speaking to a single-stream device solely.
Ennis noted that STBC also improves the signal-to-noise ratio, which makes faster rates and farther distances possible. "I think this is going to be a popular optional feature," he said.
Aggregation MPDUs (MAC Protocol Data Units). While sounding obscure, this is yet another way by which 802.11n can eke out improved speeds. For long sequences of data, aggregation MPDUs lets a Wi-Fi system create a long frame, reducing all the overhead required to send a packet. (Every packet has origin and destination information, a preamble, and other data that adds overhead.)For video, for instance, Ennis says that this kind of aggregation can improve throughput, although probably not by double-digit percentages. "It's not as dramatic an improvement as say using more spatial streams, or using 40 MHz channels," he said.
Currently, the Wi-Fi Alliance tests aggregation only if a manufacturer's access point sends these aggregated frames; it checks that a station can properly receive such frames, which can be interpreted under earlier 802.11n drafts. The new optional certification tests for aggregated frames sent by both stations and access points. (If included, it must be tested.)
Three spatial streams. This last one is quite simple. The Wi-Fi Alliance can now test for devices that send three streams of data across space up from two streams of data. Ultimately, we should see devices that can handle four, with a maximum raw symbol rate of 600 Mbps with wide channels in 5 GHz.
Those are the technical bits. The a/b/g/draft n labeling can only go so far and there should be more news on that front soon.
IEEE Ratifies 802.11n
The IEEE Standards Board has formally ratified the 802.11n standard (802.11n-2009, to be extraordinarily specific). It took seven years and involved 400 members from 20 countries. Somebody deserves a vacation.
Successor standards committee's are already underway, of course, but it's likely years before we see products based on 802.11ac (6 GHz and below) and 802.11ad (60 GHz), both of which aim for speeds of 1 Gbps and faster.
Somebody go put masking tape over the word "draft" on all those Wi-Fi boxes.
As far as any firmware revisions based on tweaky late changes to the spec, it's unlikely. From what I can tell from colleagues and the Wi-Fi Alliance, it's much more likely that newer devices will add features than current devices will see (or require) firmware changes.
On 7-August-2009, I wrote up the four major additional features coming to the Wi-Fi certification process, some of which were dependent on the late-stage draft changes in 802.11n. See "The Fine Points of Optional Wi-Fi 802.11n Certification."
The four new certification elements mostly, but not entirely, related to improving raw speed or net throughput.
Successor standards committee's are already underway, of course, but it's likely years before we see products based on 802.11ac (6 GHz and below) and 802.11ad (60 GHz), both of which aim for speeds of 1 Gbps and faster.
Somebody go put masking tape over the word "draft" on all those Wi-Fi boxes.
As far as any firmware revisions based on tweaky late changes to the spec, it's unlikely. From what I can tell from colleagues and the Wi-Fi Alliance, it's much more likely that newer devices will add features than current devices will see (or require) firmware changes.
On 7-August-2009, I wrote up the four major additional features coming to the Wi-Fi certification process, some of which were dependent on the late-stage draft changes in 802.11n. See "The Fine Points of Optional Wi-Fi 802.11n Certification."
The four new certification elements mostly, but not entirely, related to improving raw speed or net throughput.
ARUBA NETWORKS WINS MOBILE STAR AWARDS FOR WIRELESS LAN MANAGEMENT
AirWave Wireless Management Suite and Virtual Branch Networking Solution Win Superstar Awards, While the RAP-2 Remote Access Point Grabs a Shining Star
Aruba, a global leader in 802.11n wireless LANs and secure mobility solutions, announced that it has been awarded three awards as part of the eighth annual Mobile Star Awards(TM) program. The program promotes the top mobile products and deployments across a broad range of categories including applications, enterprise software, and wireless network products. Superstar awards, the highest honor, were conferred upon Aruba's AirWave Wireless Management Suite (AWMS) and Virtual Branch Networking (VBN) solutions. Aruba's RAP-2 Remote Access Point received a Shining Star award.
AWMS is the only network management software to deliver full visibility and control over multi-vendor wireless networks. A single, easy-to-use console provides a window into all aspects of network operation, simplifying the work of network engineers, Help Desk staff, IT managers, and security analysts. The suite includes four primary components:
* AirWave Management Platform (AMP)
* VisualRF(TM) Location and Mapping Module
* RAPIDS(TM) Rogue Detection Module
* AirWave Master Console & Failover Servers
AirWave OnDemand, a cloud-based enterprise-class network management service, is the newest extension of the AWMS product line. Using sophisticated tools previously available only to large organizations with large budgets, AirWave OnDemand allows even the smallest organization to efficiently manage, monitor, and control its network.
The VBN solution dramatically simplifies the complexity and cost of deploying a remote solution at branches with one to many users. Complex configuration, management, software updates authentication, intrusion detection, and remote site connectivity tasks are handled by powerful data center-based Aruba controllers. Centralizing these services in the controllers enables the branch office equipment to be greatly simplified and cost reduced. The virtualized functions are transport-independent, so any wide-area network -- including inexpensive cable, DSL, and 3G cellular -- can be used to connect branches offices.
The RAP-2, a component of VBN, securely connects remote users with enterprise network services and applications. Featuring authenticated wired and Wi-Fi access, and with a list price of just $99, the RAP-2 is a very economical solution for branch offices and fixed teleworkers.
"'Go Mobile' readers are among the industry's most savvy mobile business users, so Mobile Star Awards winners can claim they are the users' choice," says Jon Covington, MobileVillage founder and president. "Winners are chosen by real users based on real results, not hype. New mobile services competed on an equal footing with well-established solutions, and both nominees and winners are the new leaders to watch."
Mobile Star winners are chosen by subscribers to Go Mobile(R), MobileVillage's free newsletter about mobile technology from news Web sites such as Cnet, Engadget, Gizmodo, PC Magazine, Computerworld, and AppScout.
Aruba, a global leader in 802.11n wireless LANs and secure mobility solutions, announced that it has been awarded three awards as part of the eighth annual Mobile Star Awards(TM) program. The program promotes the top mobile products and deployments across a broad range of categories including applications, enterprise software, and wireless network products. Superstar awards, the highest honor, were conferred upon Aruba's AirWave Wireless Management Suite (AWMS) and Virtual Branch Networking (VBN) solutions. Aruba's RAP-2 Remote Access Point received a Shining Star award.
AWMS is the only network management software to deliver full visibility and control over multi-vendor wireless networks. A single, easy-to-use console provides a window into all aspects of network operation, simplifying the work of network engineers, Help Desk staff, IT managers, and security analysts. The suite includes four primary components:
* AirWave Management Platform (AMP)
* VisualRF(TM) Location and Mapping Module
* RAPIDS(TM) Rogue Detection Module
* AirWave Master Console & Failover Servers
AirWave OnDemand, a cloud-based enterprise-class network management service, is the newest extension of the AWMS product line. Using sophisticated tools previously available only to large organizations with large budgets, AirWave OnDemand allows even the smallest organization to efficiently manage, monitor, and control its network.
The VBN solution dramatically simplifies the complexity and cost of deploying a remote solution at branches with one to many users. Complex configuration, management, software updates authentication, intrusion detection, and remote site connectivity tasks are handled by powerful data center-based Aruba controllers. Centralizing these services in the controllers enables the branch office equipment to be greatly simplified and cost reduced. The virtualized functions are transport-independent, so any wide-area network -- including inexpensive cable, DSL, and 3G cellular -- can be used to connect branches offices.
The RAP-2, a component of VBN, securely connects remote users with enterprise network services and applications. Featuring authenticated wired and Wi-Fi access, and with a list price of just $99, the RAP-2 is a very economical solution for branch offices and fixed teleworkers.
"'Go Mobile' readers are among the industry's most savvy mobile business users, so Mobile Star Awards winners can claim they are the users' choice," says Jon Covington, MobileVillage founder and president. "Winners are chosen by real users based on real results, not hype. New mobile services competed on an equal footing with well-established solutions, and both nominees and winners are the new leaders to watch."
Mobile Star winners are chosen by subscribers to Go Mobile(R), MobileVillage's free newsletter about mobile technology from news Web sites such as Cnet, Engadget, Gizmodo, PC Magazine, Computerworld, and AppScout.
12.19.2009
Wi-Fi network
The city hopes to buy the system, originally built by EarthLink, for $2 million
The city of Philadelphia plans to buy a controversial Wi-Fi network that was built by EarthLink in 2006 but sold only two years later as the struggling ISP pulled out of the municipal wireless business.
The Philadelphia network was conceived in the middle of this decade with the vision of blanketing the city with wireless Internet access. The city planned the network in part to make sure low-income residents would have some form of Internet access. Many other U.S. cities followed Philadelphia's lead with similar plans, which EarthLink offered to carry out, but soon the ISP pulled out of the business. The Philadelphia network, which covered about 75 percent of the city, was saved from demolition in 2008 when EarthLink sold it to Network Acquisition Co. (NAC), a local company.
Pending city council approval, Philadelphia will buy the network for US$2 million and primarily use it for city operations, said city spokesman Douglas Oliver. Over the next five years, the city would invest about $17 million to add public-safety radios to the infrastructure and finish building it out to cover the whole city. By that time, the investments will have more than paid off in savings from more efficient city operations, said Chief Technology Officer Allan Frank. For example, workers can be more productive by filing reports from the field instead of going back to the office.
Free public Internet access will be available in some public spaces, and eventually, the city may bring in revenue through partnerships with government agencies and educational institutions, Oliver said. But the plan to use Wi-Fi to democratize the Internet has gone by the wayside.
"The digital divide is still real, and it is still something that needs to be addressed. Perhaps that was not the model to address it, but it makes the cause no less worthy," Oliver said.
NAC will be selling the network to Philadelphia for about the same price it paid to EarthLink. To pay for it, the city will tap into a capital fund for public safety as well as a federal Department of Homeland Security grant for installing security cameras around the city. Those cameras will be connected via Wi-Fi. Building a similar network from scratch would cost about $30 million, the city estimated.
Philadelphia is probably making a good investment, according to Craig Settles, an independent municipal networking analyst who has written a book about the city's Wi-Fi odyssey. Cities can save a lot of money by equipping field employees with Wi-Fi, as well as applying the network to new technologies, such as electronic parking meters. Those meters cost less to operate because there is no cash to handle, and they can increase revenue by detecting meter violations as soon as they occur, he said.
Municipal Wi-Fi plans for places such as San Francisco, Chicago and Silicon Valley generated excitement partly because of the promise of access to Wi-Fi anywhere, in some cases for free. At companies such as EarthLink, the idea of paid or ad-supported Wi-Fi for consumers became a distraction from the viable business model of city services, Settles said.
"It was the reason that those networks failed, because it became the tail that wagged the dog," Settles said. The cost was high for cities that bought into that dream. "Most cities had no financial investment, but they lost time and they lost political equity," he said.
Settles pointed to Houston, Oklahoma City, Minneapolis, and Providence, Rhode Island, as cities that have had success with municipal Wi-Fi. Only one of those networks, in Minneapolis, is used for paid consumer Internet access, he said.
500mW Outdoor Wi-Fi Access Point/Client/Repeater Bridge
The city of Philadelphia plans to buy a controversial Wi-Fi network that was built by EarthLink in 2006 but sold only two years later as the struggling ISP pulled out of the municipal wireless business.
The Philadelphia network was conceived in the middle of this decade with the vision of blanketing the city with wireless Internet access. The city planned the network in part to make sure low-income residents would have some form of Internet access. Many other U.S. cities followed Philadelphia's lead with similar plans, which EarthLink offered to carry out, but soon the ISP pulled out of the business. The Philadelphia network, which covered about 75 percent of the city, was saved from demolition in 2008 when EarthLink sold it to Network Acquisition Co. (NAC), a local company.
Pending city council approval, Philadelphia will buy the network for US$2 million and primarily use it for city operations, said city spokesman Douglas Oliver. Over the next five years, the city would invest about $17 million to add public-safety radios to the infrastructure and finish building it out to cover the whole city. By that time, the investments will have more than paid off in savings from more efficient city operations, said Chief Technology Officer Allan Frank. For example, workers can be more productive by filing reports from the field instead of going back to the office.
Free public Internet access will be available in some public spaces, and eventually, the city may bring in revenue through partnerships with government agencies and educational institutions, Oliver said. But the plan to use Wi-Fi to democratize the Internet has gone by the wayside.
"The digital divide is still real, and it is still something that needs to be addressed. Perhaps that was not the model to address it, but it makes the cause no less worthy," Oliver said.
NAC will be selling the network to Philadelphia for about the same price it paid to EarthLink. To pay for it, the city will tap into a capital fund for public safety as well as a federal Department of Homeland Security grant for installing security cameras around the city. Those cameras will be connected via Wi-Fi. Building a similar network from scratch would cost about $30 million, the city estimated.
Philadelphia is probably making a good investment, according to Craig Settles, an independent municipal networking analyst who has written a book about the city's Wi-Fi odyssey. Cities can save a lot of money by equipping field employees with Wi-Fi, as well as applying the network to new technologies, such as electronic parking meters. Those meters cost less to operate because there is no cash to handle, and they can increase revenue by detecting meter violations as soon as they occur, he said.
Municipal Wi-Fi plans for places such as San Francisco, Chicago and Silicon Valley generated excitement partly because of the promise of access to Wi-Fi anywhere, in some cases for free. At companies such as EarthLink, the idea of paid or ad-supported Wi-Fi for consumers became a distraction from the viable business model of city services, Settles said.
"It was the reason that those networks failed, because it became the tail that wagged the dog," Settles said. The cost was high for cities that bought into that dream. "Most cities had no financial investment, but they lost time and they lost political equity," he said.
Settles pointed to Houston, Oklahoma City, Minneapolis, and Providence, Rhode Island, as cities that have had success with municipal Wi-Fi. Only one of those networks, in Minneapolis, is used for paid consumer Internet access, he said.
500mW Outdoor Wi-Fi Access Point/Client/Repeater Bridge
Power over Ethernet
Friday, December 18, 2009
Power Over Ethernet
PoE, With Advances in technology smaller devices i.e Mini tower computers, laptop. and portable network devices become small enough both physically and electronically to not only use the Ethernet cable to transmit data to the device, but also to send the electricity necessary to power the device.
The SLM2005 switch is ideal for conference rooms, labs, shipping and receiving departments or in marketing, design or audio and visual work-groups. The five 10/100/1000 Mbps (Gigabit Ethernet) ports enable companies to link to other Gigabit devices on the network (servers, workstations and network storage) to quickly move bandwidth-intensive files while still supporting 10/100 Mbps clients.
The SLM2005 supports the IEEE802.3af standard for Power over Ethernet (PoE) for obtaining its power over a designated PD port or from an external AC power adapter. This gives companies the option to install the switch in places where a power outlet may not be present, such as in ceilings and in walls.
The SLM2005 is able to secure the network through IEEE 802.1Q VLANs and IEEE 802.1X port authentication. For environments where IP multicast applications are used, the switch is capable of limiting the traffic to only the ports that have requested that traffic with support of IGMP Snooping. Additional QoS capabilities like IEEE 802.1p, DSCP, and 4 hardware queues make it possible to maintain good quality for real-time applications like voice and video.
The SLM2005 offers an easy-to-use browser interface for the management and configuration of the features, making it ideal for small businesses without an IT staff or that have minimal technical expertise.
12.16.2009
Earth Hour Vote Earth for Copenhagen
This video will be projected onto the Globe in City Hall Square during Earth Hour Copenhagen.
WLAN SITE SURVEY USING NETSTUMBLER HOW TO
WLAN WIFI SITE SURVEY USING NETSTUMBLER, LAPTOP AND A YAGI DIRECTIONAL ANTENNA IN KINGSTON, JAMAICA.
12.14.2009
Multiple Input, Multiple Output
IEEE 802.11n builds on previous 802.11 standards by adding multiple-input multiple-output (MIMO) 11n a (PHY) Physical Layer 1 of the OSI model. 40 MHz channels to the PHY (physical layer), and frame aggregation to the MAC layer.
With MIMO, each physical radio card had multiple radio chains - currently up to three per physical radio card. There will be up to four radio chains per radio card. A radio chain is an RF radio
connected to an RF antenna.
MIMO is a technology which uses multiple antennas to coherently resolve more information than possible using a single antenna. In 802.11a,b, and g systems multiple transmissions are not possible without significant impact to throughput and link integrity.
12.13.2009
Motorola Expands 4G Broadband
Motorola expands 4G broadband during 2009 as it builds momentum for WiMAX and LTE in 2010
Lands more WiMAX contracts, gains TD-LTE foothold and expands portfolio of products to help operators worldwide deliver experiences to their customers
The Home & Networks Mobility business of Motorola, Inc.
“Wireless broadband is the utility of the 21st century, and Motorola has the solutions in both WiMAX and LTE that will meet consumer demand and operator requirements for network efficiency,” said Bruce Brda, senior vice president and general manager, Wireless Networks, Motorola Home & Networks Mobility. “Motorola’s legacy of expertise in wireless broadband, IP networking, video and services, coupled with our portfolio of proven solutions, can help operators go to market quickly to maximize their competitive advantage as they deploy new networks or evolve their existing networks to 4G.”
Motorola’s 4G progress in 2009 was marked with accomplishments in both LTE and WiMAX that have positioned it well for further momentum in 2010. In addition, Motorola has stated its commitment to WiMAX 802.16m as it expands its product portfolio and customer base to maintain its leadership position in WiMAX. The company also continues its active participation in numerous standards bodies as they refine specifications for various technologies that will enable faster broadband access.
According to Motorola’s 2009 Media Engagement Barometer , a study recently commissioned by the Home & Networks Mobility business to gain insights from American consumers, the need to stay connected and to have access to personal content transcends generations. The overwhelming desire to be constantly connected was expressed by 80 percent of the Millennials and 78 percent of both the GenXers and Boomers who participated in the survey. The barometer findings clearly show how networking technologies have had a powerful impact in integrating the different facets of people’s lives, and why delivering on the promise of 4G is so important to Motorola’s Wireless Networks business.
Motorola’s early commitment to WiMAX has given it vast experience and expertise in designing, planning, optimizing and managing Orthogonal Frequency Division Multiplexing (OFDM) mobile broadband networks. It also has yielded tremendous insight into perfecting the 4G network scheduler, the master controller of the radio access network that prioritizes voice and data traffic.
Motorola is leveraging this extensive OFDM, multiple-in/multiple out (MIMO), all-IP wireless broadband experience, and expertise in the 4G scheduler to deliver a complete award-winning LTE solution that will support both FDD and TD-LTE. Its first commercial LTE deployments will be based on third-generation WiMAX products that have been proven and field-hardened and for which algorithms have been optimized to deliver best performance in a real-world environment.
”With our experience from WiMAX we can get our LTE customers to market faster and with less risk,” Brda said. “Our deployment, management and optimization of many large-scale commercial WiMAX networks around the world gives us operations-level experience which our research and development teams use to make better and more stable LTE solutions.”
Lands more WiMAX contracts, gains TD-LTE foothold and expands portfolio of products to help operators worldwide deliver experiences to their customers
The Home & Networks Mobility
“Wireless broadband is the utility of the 21st century, and Motorola has the solutions in both WiMAX
Motorola’s 4G progress in 2009 was marked with accomplishments in both LTE and WiMAX that have positioned it well for further momentum in 2010. In addition, Motorola has stated its commitment to WiMAX 802.16m as it expands its product portfolio and customer base to maintain its leadership position in WiMAX. The company also continues its active participation in numerous standards bodies as they refine specifications for various technologies that will enable faster broadband access.
According to Motorola’s 2009 Media Engagement Barometer
Motorola’s early commitment to WiMAX has given it vast experience and expertise in designing, planning, optimizing and managing Orthogonal Frequency Division Multiplexing (OFDM) mobile broadband networks. It also has yielded tremendous insight into perfecting the 4G network scheduler, the master controller of the radio access network that prioritizes voice and data traffic.
Motorola is leveraging this extensive OFDM, multiple-in/multiple out (MIMO), all-IP wireless broadband experience, and expertise in the 4G scheduler to deliver a complete award-winning LTE solution that will support both FDD and TD-LTE. Its first commercial LTE deployments will be based on third-generation WiMAX products that have been proven and field-hardened and for which algorithms have been optimized to deliver best performance in a real-world environment.
”With our experience from WiMAX we can get our LTE customers to market faster and with less risk,” Brda said. “Our deployment, management and optimization of many large-scale commercial WiMAX networks around the world gives us operations-level experience which our research and development teams use to make better and more stable LTE solutions.”
The Institute of Electrical and Electronic Engineer
The IEEE creates the industry standards in the United States and in many parts of the world. The IEEE created the 802.11-2007 standard and subsequent WLAN amendments. The IEEE creates the standards within the confines of regulatory domains. The IEEE website is www.ieee.org
The body responsible for IEEE 802.3 (Ethernet), 802.11 (WLAN), and many other specifications. The IEEE creates standardized data communications protocols for Layers 1 and 2 of the OSI model.(Open System Interconnection)
Layers of OSI Model
Layer 7 | Network Application
Layer 6 | Presentation
Layer 5 | Session
Layer 4 | Transport
Layer 3 | Network
Layer 2 | Data - Link ( is your Ethernet protocol and Ethernet addressing * MAC Address
*LLC sublayer
*MAC sublayer
Layer 1 | Physical - traffic is going across your network medium ( such as your network cable or your wireless air waves)
12.11.2009
CWNA: Certified Wireless Network Administrator Official Study Guide
1. Radio Frequency (RF) Technologies
RF Fundamentals
RF Mathematics
RF Signal and Antenna Concepts
RF Antenna Accessories
2. IEEE 802.11 Regulations and Standards
Spread Spectrum Technologies
IEEE 802.11-2007 Standard
IEEE 802.11 Industry Organizations and Their Roles
3. IEEE 802.11 Protocol and Devices
IEEE 802.11 Protocol Architecture
IEEE 802.11 MAC and PHY Layer Technologies
WLAN Infrastructure and Client Devices
4. IEEE 802.11 Network Implementation
IEEE 802.11 Network Design, Implementation, and Management
IEEE 802.11 Network Troubleshooting
Power over Ethernet (P0E)
WLAN Architectures
5. IEEE 802.11 Network Security
IEEE 802.11 Network Security Architecture
IEEE 802.11 Network Security Analysis, Performance Analysis, and Troubleshooting
IEEE 802.11 Network Security Policy Basics
6. IEEE 802.11 RF Site Surveying
IEEE 802.11 Network Site Survey Fundamentals
IEEE 802.11 Network Site Survey Systems and Devices
RF Fundamentals
RF Mathematics
RF Signal and Antenna Concepts
RF Antenna Accessories
2. IEEE 802.11 Regulations and Standards
Spread Spectrum Technologies
IEEE 802.11-2007 Standard
IEEE 802.11 Industry Organizations and Their Roles
3. IEEE 802.11 Protocol and Devices
IEEE 802.11 Protocol Architecture
IEEE 802.11 MAC and PHY Layer Technologies
WLAN Infrastructure and Client Devices
4. IEEE 802.11 Network Implementation
IEEE 802.11 Network Design, Implementation, and Management
IEEE 802.11 Network Troubleshooting
Power over Ethernet (P0E)
WLAN Architectures
5. IEEE 802.11 Network Security
IEEE 802.11 Network Security Architecture
IEEE 802.11 Network Security Analysis, Performance Analysis, and Troubleshooting
IEEE 802.11 Network Security Policy Basics
6. IEEE 802.11 RF Site Surveying
IEEE 802.11 Network Site Survey Fundamentals
IEEE 802.11 Network Site Survey Systems and Devices
5GHz vs. 2.4GHz Spectrum
Today there are two primary 802.11 standards used in the enterprise:
- 802.11b/g operating in the 2.4GHz radio spectrum
- 802.11a operating in the 5GHz radio spectrum
| 5GHz | 2.4GHz | Advantage Defined | |
|---|---|---|---|
| Bandwidth | 54/300Mbps | 54/300Mbps | Both choices support up to 54Mbps of bandwidth today and up to 300Mbps when the new 802.11n standard is deployed. |
| Channels | 24 | 3 | Restrictions in the 2.4GHz band limit the number of simultaneously channels to 3, while the 5GHz band offers up to 24. |
| Capacity | 3.45Gbps | 450Mbps | The 24 channels available with 5GHz far exceed the capacity of 2.4GHz. 802.11a = 1.24Gbps / 802.11n = 3.45Gbps (5GHz) 802.11g = 162Mbps / 802.11n = 450Mbps (2.4GHz) |
| Interference | Low | High | Wi-Fi in 2.4GHz competes with microwaves, Bluetooth, wireless phones, etc. resulting in a very noisy environment. The 5GHz band is considerably cleaner. |
| Channel Planning | Flexible | Restricted | With 8 times the number of channels to chose from in the 5GHz band, planning is far simpler than the 2.4GHz band. |
| Triple Play Support | Optimal | Limited | Only 5GHz supports the bandwidth, capacity, and throughput required for enterprise quality voice, video, and data applications. |
| 802.11n | Optimal | Limited | Although 802.11n supports both bands, the available channels, bandwidth, and client capacity makes the 5GHz band the obvious choice. |
| Range | Good | Better | Even though the 2.4GHz band has greater range than 5GHz, proper deployment using directional antennas can eliminate any issue. |
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