Broadcom’s 5G Wi-Fi chips will triple bandwidth for wireless home networking

January 6, 2014 5:00 AM

 

Broadcom is unveiling new 5G Wi-Fi chips for home networking devices that can triple the typical bandwidth for wireless Internet access in the home.

The Irvine, Calif.-based chip maker made the announcement at the 2014 International CES trade show that takes place this week in Las Vegas.

The new wireless combo chip will make it easier to stream video through routers, gateways, set-top boxes, digital TVs, and game consoles in the home. That’s important as web-based video usage explodes in the home, thanks to video streaming services like Netflix.

Broadcom is providing two new chips for 5G Wi-Fi systems that will help alleviate the logjam in homes as more devices — such as remotes, speakers, and game controllers — use Bluetooth and Wi-Fi. The chips can reduce interference when one person plays an online game and another streams a movie to a tablet or smart TV.

The BCM43569 wireless networking chip lets a smart TV receive both Wi-Fi and Bluetooth signals simultaneously. And Broadcom’s BCM43602 chip offloads a lot of processing from a central processing unit (CPU) for Wi-Fi networking. Both chips support beamforming, or taking advantage of noise to increase available bandwidth.

“As the first company to deliver 5G Wi-Fi across all product segments, Broadcom continues to lead innovation and engineer even more powerful next-generation 5G Wi-Fi products that support today’s content-hungry consumer,” Rahul Patel, vice president of marketing for wireless connectivity combos at Broadcom, told VentureBeat in an interview. “Our new advanced solutions bring consumers an elevated video streaming experience across the wirelessly connected home and provide OEMs with the benefits of improved system cost and form factor.”

“By the end of 2014, 802.11ac is expected to be included in more than 50 percent of total Wi-Fi ICs shipped,” said Phil Solis, research director at market research firm ABI Research. “By maximizing the wireless connectivity performance in connected home devices, Broadcom continues to help drive the industry adoption of 802.11ac technology across all product segments.”

Both chips are available in prototype quantities now.

What Else Is In the 5 GHz Spectrum? Hint: It’s Not Just Weather Radar

Guest Post written by Lee Badman

As I continue to get ready for my own venture into 11ac, I came across some pretty fascinating information about 5 GHz. I’ve been brushing up on how the state of 5 GHz spectrum applies to the Wi-Fi realm now, and what People of Lofty Title are wrestling with regarding future use of this slice of frequencies. Standby, because I’m going to dazzle you with some pretty darn macho terminology. (As a bonus, I shall invoke the name of Matthew Gast thricely in the following paragraph.)

But first, let’s set the stage.

WLAN designers and admins (hopefully) know about subjects like DFS (Dynamic Frequency Selection) and TPC (Transmit Power Control) and how they relate to weather radar in 5 GHz (cue the Matthew Gast music there, Part I). Also, hopefully we are all familiar with the last announcement about the WLAN world possibly being gifted with a fat swath of additional 5 GHz frequencies for the greater wireless good, made by ex-FCC Chairman Julius Genachowski (cue the Mathew Gast music again, Part II and Part III). It’s all great stuff, very relevant, and is techno-fodder that you should care about given the channel-hungriness of 802.11ac. But that’s not why we’re gathered here on this page.

As I was poking around, I came across this rather dry (at first glance) looking document by the Department of Commerce. It gets deeper into the many challenges of sharing more of the unlicensed 5 GHz goodness with WLANers while also protecting the interests of the licensed/federal/important users that also happen to be in this spectrum. And here’s where it gets interesting. Sure, weather radar is important- but the list of other users in 5 GHz is a veritable who’s who of cool stuff. 

In all fairness to those of you who don’t know- I spent 10 years in the US Air Force in the Electronic Warfare career field, and maybe that’s why this sort of detail jazzes me (yes, some of what I did back in the day is on this list). Feast your eyes on the other occupants that live on 5 GHz Street, as noted in the unclassified Dept. of Commerce document:

  • Highly mobile ground-based, shipborne, and airborne radar systems
  • Range and tracking radars at DoD test and training ranges (get to know the C-Band)
  • DoD comms systems
  • Naval tactical radars like surface search, navigation, and fire control
  • A bunch of stuff on Coast Guard cutters used in law enforcement, search and rescue, etc
  • NASA- test and launch instrumentation, tracking of rockets, missiles and satellites
  • NOAA’s Hurricane Hunters have systems in 5 GHz
  • A whole range of operational goodies dealing with Unmanned Aircraft Systems (UAS) like data links, video targeting
  • Spaceborn Synthetic Aperture Radars, including Canada’s RADARSAT (fascinating if you don’t know about this one)
  • Electronic Warfare systems
  • Lots more…

Some of these are site-specific and one-of-a-kind. Others are widespread, mobile, and out of the public eye. But they all use 5 GHz (albeit different discreet bandwidths within 5 GHz), so it’s amazing that the WLAN community has been able to come this far in the U-NII bands at all. It’s even more amazing that we’re likely to get more freqs made available, knowing who also uses it.

The Commerce Doc is really a great read if this stuff interests you, and I recommend it. If the specifics are too heavy for you, just go back through my abbreviated list here and apply “oohs” and “aahs” as you see fit.

(Note- the Doc projects completion of the co-existance studies later in 2014… let’s see what happens.)

 

 

 

What you need to know about the iPhone 5 and 5GHz Wi-Fi

iphone5_5GHzwifi.com

iphone5_5GHzwifi.com

The iPhone 5 is Apple’s first mobile device to support Wi-Fi connections on the 5GHz band. Here’s what it means for you.

 Is iPhone 5 the first smartphone to support 5GHz?

No. A few Android-based rivals, such as the HTC One X and the Samsung Galaxy S III, offer dual-band Wi-Fi. A growing number of new phones will have 5GHz support.

What is 5GHz Wi-Fi?

5GHz is the “other frequency” that Wi-Fi client radios can use, besides 2.4GHz, to connect to an access point or hotspot.

Why would I want to use it?

First, because the 2.4GHz band is crowded, and therefore has a greater chance of interference. There are lots of devices are using it: Lots of other Wi-Fi devices, including embedded Wi-Fi radios, but also non-Wi-Fi radios like Bluetooth, cordless phones, baby monitors, and stuff like microwave ovens.

Client Wi-Fi radios that support only 802.11g can only connect on 2.4GHz. 802.11a, which so far has not been widely used, runs on 5GHz. 802.11n, which has much higher data rates, can run on either band but most smartphones today that have 11n, such as iPhone 4 and 4S, only run it on 2.4GHz.

And even when the client radio could run on either band, a lot of them today still “decide” to connect on 2.4GHz and stick with it, even when a better connection is available. Vendors and IEEE are working on various technologies to address this, including shifting more control over the connection, and optimizing it to the access point/network, instead of the client.

Second, the 2.4GHz band has only three non-overlapping, 20MHz-wide channels: In crowded environments—lots of access points, lots of clients—that can make it hard to get a channel connection. And fewer channels means lower aggregate capacity on the network side.

So what’s different about 5GHz?

By contrast, the 5GHz band has, for now, many fewer Wi-Fi clients, and 23 20MHz-wide, non-overlapping channels.

In the 802.11n radio standard, one way that data rates increase dramatically is by combining (or “bonding”) two of these channels into a wider 40MHz wireless“pipe.” In 2.4GHz, you only have the three channels, and can create only one 40MHz channel.

Apple says that iPhone 5 will deliver a maximum 150Mbps data rate. This would mean using 802.11n, with a single data stream, and a 40MHz channel. Actual throughput will be much less.

How does 5GHz affect network capacity?

“5GHz support on an iPhone is a wonderful thing for Wi-Fi,” says William Kish, CTO and co-founder of Ruckus Wireless. “It increases aggregate capacity in challenging environments by something like a factor of 10-12 compared to 11n on 2.4GHz.”

Kish defines aggregate capacity as “the total capacity available to all simultaneous users across all of the APs in a given area.”

“The higher aggregate capacity is mostly a function of the much larger amount of bandwidth (e.g., the [much greater] number of channels) available in the 5GHz band as well as the more capacity-favorable propagation characteristics of the 5GHz spectrum,” Kish says.

For example, an 802.11g network offers 54Mbps of capacity on each of three 2.4GHz channels, for a total capacity of 162Mbps. 802.11a offers the same 54Mbps, but in theory its capacity is much larger due to the larger number of 5GHz channels.

For 802.11n, the numbers are even greater: 150Mbps per channel, for 450Mbps in the 2.4GHz band, and 3.45Gbps in 5GHz. In all cases the actual throughput users get is much less.

What does that mean for throughput?

Kish was recently at the Time Warner Cable Arena in Charlotte, N.C., where a Ruckus Wi-Fi network had been installed, for a live event. He speed-tested his Samsung Galaxy S III smartphone in the network: 60.33Mbps download, and 58.78Mbps upload.

“60Mbps is a serious amount of throughput to a mobile device under real-world conditions!” he says. “I have my fingers crossed that the iPhone 5 delivers similar results.”

Are there any drawbacks to 5GHz?

At the same power level, a 5GHz signal has a shorter wavelength than a 2.4GHz signal. That means it propagates shorter distances. From a client perspective, for example using a Starbucks hotspot or a well-designed hotzone or enterprise WLAN planned for 5GHz, users often may not be affected by either of those characteristics.

Higher-gain antennas and/or increased transmit power (though this is regulated by the Federal Communications Commission) can offset the 5GHz propagation.

Another issue is how the phone will decide which band to use: Will it be set (or settable) to “prefer” 5GHz over 2.4GHz, so the choice is automatic? Or will you be prompted for your preference? Or do you have to manually select one or other?

June 2012 blog post at WLAN vendor Aruba Networks noted that the vendor’s testing of 5GHz mobile devices found “that handover performance [from one access point to another] for a fast-moving device is not quite as good when both bands are enabled as it was for 2.4GHz only … this is probably due to the larger number of channels that must be scanned. The chip vendors will need to tweak their probing and selection algorithms to tighten this up, and there are some new standard features coming that will help. But this is a minor concern.”

What Wi-Fi chip is in the iPhone 5?

We don’t know exactly, yet, until the phone is released and it gets the “tear-down” treatment. But historically, Apple has sourced the radio from Broadcom. The iPhone 4S uses the Broadcom BCM4330—at the time last year Broadcom’s newest WLAN—Bluetooth, and FM combo chip. It was also used in the Samsung Galaxy S II and, according to Kish, in the newer S III.

That chip supports both bands, but only the 2.4GHz band has been “turned on” in the past in most smartphones.

Can Apple make any other tweaks to boost Wi-Fi performance?

In their in-depth review last year of iPhone 4S, Anand Lal Shimpi and Brian Klug, of AnandTech.com, found the 4S Wi-Fi/Bluetooth antenna, repositioned to the top corner of the phone, had “slightly better received signal strength … compared to a [iPhone] 4 side by side, and upon checking the FCC documents learned the 4S’ WLAN antenna has a peak gain of -1.5 dBi compared to -1.89 dBi on the 4, making it better than the previous model.” The higher gain, loosely understood as sensitivity, improves the signal strength and helps sustain the higher throughput connection.

For iPhone 5, Apple has added two glass “RF windows” on the back, at top and bottom. There might also be antenna improvements. Together, these could improve signal strength for the phone.

The more powerful A6 CPU, Apple’s system-on-chip or SoC, in the iPhone 5 may also have an impact. In their review of the 4S, the authors noted: “I’m starting to think that the bigger boost is actually thanks in part to a faster SoC.” Apple says the A6 delivers twice the performance for new phone as for the 4S.

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5 GHz: The band that never was

Written by: Scott Stapleton
Perth, Western Australia.  Senior Wireless Engineer CCNP Wireless, CWNA, CCNP, CCSP Tuesday, 30 October 2012 http://phasedcoexistence.blogspot.com/2012/10/5-ghz-band-that-never-was.html

In early 2009 I started working on a high density education deployment. I tried looking at every available option to wring the last piece of performance from the WLAN design. This was prior to the ratification of the 802.11n standard, which didn’t come until September of that year. What was immediately apparent was how important the 5 GHz band was going to be to achieving this goal.
At the time the Wi-Fi alliance had been certifying 802.11n Draft 2.0 gear for around two years. Because no mandatory new features were added to the final ratified standard, all Draft 2.0 gear was able to successfully interoperate with gear that came about after the standard was finally ratified. This certification was a great move from the Wi-Fi Alliance because it meant that there was a reasonably large installed base of compatible clients to make use of the 802.11n APs upon ratification, at least in the laptop space. Essentially the clients had a two-year head start. This was doubly important due to the large delays with getting 802.11n over the line. By the time it arrived in late 2009, it was desperately needed in areas such as education where one laptop (or other device) per child was starting to become the norm.
The real key to making the most out of high-density deployments is 802.11n support in the 5 GHz band. This doesn’t necessarily mean that all of your clients should be in the 5 GHz band as you may be missing out on available airtime in the 2.4 GHz band – just that if all (or more realistically, most) of your clients are dual-band capable then at least you have the 5 GHz option at your disposal!
In early 2009 it was hard to gauge how many clients would be released with dual-band support. At the time I thought that two-years post-ratification (late 2011) most clients released would support not only 802.11n but also the 5 GHz band. Two years later the majority of clients did support 802.11n however unfortunately this was not the case when it came to 5 GHz support. Not only that but early experiences with the 5 GHz band on many devices (though certainly not all) has been underwhelming largely due to poor implementations by client vendors.
The Laptops
Initially most laptop drivers I tested did not prefer the band and many would jump between bands during use of the client. In addition, Cisco didn’t offer a band steering option early on and when they did introduce one (Band Select) it was CLI-only and the release notes stated that it should NOT be used. In other words, it was buggy. Later it made its way to the GUI. With bugs ironed out in the Band Select code and with improved laptop drivers, laptops began to stick to the 5 GHz band.
Most of the new laptops that I was testing in 2009 offered dual-band support so when I started a new role in late 2010 I was very surprised that my corporate laptop provided only single-band support. Not only was it 2.4 GHz-only but it didn’t even provide MIMO or support Short Guard Interval – 65 Mbps was the top data rate! This came as a big surprise but since then I have seen plenty of ultra-lightweights’ and Ultrabooks that likewise only provide single-band support.
Then of course there is band and channel support within the 5 GHz band. With the 5 GHz band broken up into five separate bands (UNII-1, UNII-2, UNII-2e, UNII-3 and ISM) there are often incompatibility issues between what bands the infrastructure supports and what the client supports. Much of this comes down to what regulatory domain your infrastructure/client vendor intends your equipment to operate in and the issues this causes when their vision doesn’t fit with yours. These vendors and the original 802.11 standard seem to have forgotten about the realities of globalisation!
In my utopian-vision, world-peace would result in real universal standards. This would eliminate the 5 GHz incompatibilities we see amongst infrastructure equipment and clients :)
For example, back in early 2009 I looked into why Cisco didn’t offer their APs in a SKU for the Australian market. Although legally we’re able to use the UNII-2e band, we get thrown into the lowest common denominator –N regulatory domain when purchasing Cisco APs. Of course we could purchase the US –A APs but then you have the issue of client support. There is no point in allowing your APs to use the UNII-2e band if few of your clients support it. Whilst many clients may be unable to use the UNII-2e band in Australia currently, I hope to see this change once 802.11ac and its larger channel widths take hold. As far as I can see the only reason an Australian SKU doesn’t exist is that Cisco doesn’t see Australia as a large enough market and no one has put pressure on them to support it. Whilst it would have been nice to have UNII-2e support here for 802.11n when using 40 MHz channels in high density environments, it is all the more important with the 80 MHz channels offered by 802.11ac, assuming you have a use case for such wide channels (I’m ignoring 160 MHz channels just like I ignored 40 MHz channels at 2.4 GHz!). Things are looking up though – the new Cisco 2600 series APs are available in a –Z SKU for the Australian / New Zealand market and hopefully this SKU will also be offered for forth-coming 802.11ac APs where it will really matter!
Besides this Australian/Cisco-centric issue, there are plenty of other issues when it comes down to individual 5 GHz band support from clients not supporting the UNII-2e band to clients not supporting individual channels (the Cisco 7925G’s lack of support for channel 165).
The Smartphones
It was quite some time before even a small percentage of available phones started to support the 5 GHz band. Within your average corporate or home network, this wasn’t a big deal – within a high-density environment such as a stadium deployment it certainly is! Whilst it is great to see phones supporting the 5 GHz band, mere support isn’t enough. If you’re going to offer dual-band support you’d better do it right! Let’s examine what was one of the most popular Android-based phones – the Samsung Galaxy S II. Dual-band support? – yes! Very poor RSSI at 5 GHz – yes; favouring 2.4 GHz over 5 GHz despite band steering being enabled – yes; poor support for individual 5 GHz bands – yes. With all of these issues, I consider the 5 GHz support useless on this phone. By comparison, the Samsung Galaxy S III appears to have solved most of these issues.
Then there is of course the iPhone 5, which now offers dual-band support – hopefully more inline with the Galaxy S III than the Galaxy S II.
In my mind, in 2013 we will start to see smartphones really make use of the 5 GHz band with recent client improvements and support for the band alongside an increase in stadium/BYOD/hotspot deployments. We might even start to see some 802.11ac phones – Galaxy S IV / iPhone 6 anyone!
The Tablets
Tablets have been a mixed bag when it comes to comes to 5 GHz support. There are certainly more dual-band capable tablets out there than smartphones but particularly on the Android side of the fence, it isn’t overwhelming.
In contrast to the their smart-phones, Apple has offered dual-band support from the beginning – the iPad 1, 2, 3 and now mini all support it. Dual-band android tablet support is not so great with a mixture of dual and single band tablets out there. The issues on the Samsung Galaxy S II phone also seem to exist on Samsung’s tablets. Apple’s 5 GHz tablet support seems much more solid.
5 GHz – The band that never was
So far, many 5 GHz client implementations have been underwhelming. The issue has not been with the five to six billion oscillations per second – that is, there are no significant issues with using Wi-Fi in this band.
The issue has been with both the quality and quantity of dual-band implementations from client vendors. Looking back 3+ years, I thought we’d be in a very different place by now. Things are looking up however! From improved laptop chipset drivers to improved smartphone implementations to an overall increased quantity of dual-band capable clients. With ratified enterprise-grade 802.11ac hardware on the way hopefully the lessons that client vendors have learnt from their 802.11n 5 GHz implementations pay off and we see some of the first 802.11ac clients perform solidly on the 5 GHz band. It would have been nice if the IEEE had never supported 802.11n in the 2.4 GHz band to begin with but considering work started on it almost 10 years ago, I imagine it wasn’t a realistic option back then.
In addition to the issues with client vendor implementations (or lack thereof), there is so much more that needs to be taken into account when designing for the 5 GHz band. Hopefully the knowledge gained from the v1.0 5 GHz implementations of 802.11n pays of when it comes to the v2.0 designs and implementations of 802.11ac. What about 802.11a, you may ask. That was a merely a beta!
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What’s The Difference Between 2.4 GHz and 5 GHz Wireless LAN

Wi-FiConnections.com How Are You Connected?

Wi-FiConnections.com How Are You Connected?

By Rolf Nilsson, CEO connectBlue
5/31/2012As the use of wireless technologies is increasing in the process and manufacturing industry, so is the installed base of IEEE 802.11b/g/n products that operate in the worldwide free 2.4 GHz ISM band. Besides Wireless LAN IEEE 802.11b/g/n, other wireless technologies like Bluetooth technology, IEEE 802.15.4/ ZigBee/Wireless HART and several proprietary technologies operate in the 2.4 GHz band.With so many technologies crowding the same frequency band, interference problems can occur. To make sure that industrial wireless solutions are robust, there are basically two solutions: either to carry through extensive frequency planning and use special antenna solutions (like leakage cables) in the industrial 2.4 GHz setting, or to use the 2.4 GHz band for office and IT communication and then use the 5 GHz band for the manufacturing and M2M communication.

Differences in channels and usage for the 2.4 and 5 GHz bands 

The Wireless LAN IEEE 802.11b/g radios utilize the 2.4 GHz frequency band (2.412 – 2.472 GHz) and the IEEE 802.11a radio utilizes the 5 GHz frequency band (5.180 – 5.825 GHz). IEEE 802.11n radios can operate in either frequency band. There are the following worldwide implementation attributes:

  • The 2.4 GHz ISM band provides 13 overlapping channels spread equally over the frequencies plus a fourteenth channel used in Japan with the center frequency of 2.484 GHz. This leaves available only three non-overlapping channels in the 2.4 GHz band. In order to avoid interferences between the Wireless LAN connected devices, these channels have to be used very efficiently. Installation requires careful frequency planning or expensive installation of solutions such as leakage cables. In other words, the installation costs can easily become higher than the actual wireless equipment installed.
  • The 5 GHz ISM band is divided up into sub-bands called U-NII bands (Unlicensed National Information Infrastructure) and are usually named U-NII-1, U-NII-2, U-NII-2e, and U-NII-3 where U-NII-3 is not freely available worldwide. In total, this gives 23 non-overlapping channels where four of these have limitations based on location*. Today, most available Wireless LAN solutions in the 5 GHz band use the U-NII-1 band (5.18-5.24 GHz) with frequency channels 36-48. However, there are also some suppliers that have extended the range to include the U-NII-2/2e band (5.26-5.70 GHz) with frequency channels 52-140.

Pros and cons of the 2.4 GHz and 5 GHz standards 

Wireless LAN IEEE 802.11b/g/n is already well-established with its huge installed base and a wide range of products made available. Besides its wide use, the 2.4 GHz band offers the advantage of operating in an ISM band available worldwide. Further, the achieved range using the same output power is better on 2.4 GHz compared to radios using the higher frequency 5 GHz band.

As shown in the table above, the entire 5 GHz ISM band is not available for worldwide use. Further, availability of components and products are still somewhat limited compared to the 2.4 GHz band.

The greatest strength of the 5 GHz band is the availability of 23* non-overlapping channels; 20* more channels than what is available in the 2.4 GHz band. Since there is no other wireless technology that “fights” for the radio space, the 23* available non-overlapping channels can provide a possibility for easier planning of an interference-free and stable wireless communication. Another advantage of the 5 GHz band is that the greater number of available channels provides for increased density, which means that more wireless devices can be connected in the same radio environment.

5 GHz band radar detection – Dynamic Frequency Selection (DFS) 

The use of Wireless LAN in the U-NII-2/2e bands (channel 52 -140, frequency range 5.260––5.725 GHz) requires radar detection. Within the operation context of the Dynamic Frequency Selection (DFS) function, a device shall operate as either a master or a slave. The requirements for a slave device, which is typically a client in an infrastructure, are as follows:

  • A slave device shall not transmit data before receiving an appropriate enabling signal from a master device.
  • A slave device shall stop all its data transmissions whenever instructed by a master device.
  • Devices operating as slaves shall only operate in a network controlled by a device operating as a master.

Requirements for a master device, which is typically an access point or a master in an ad hoc mode network, are different from the requirements for a slave device. The requirements for a master device are as follows:

  • A master device shall detect radar signals.
  • A master device shall only start operations on available channels.
  • During normal operation, a master device shall monitor the operating channel (in-service monitoring).
  • If a master device has detected a radar signal during in-service monitoring, the master device shall instruct all its associated slave devices to stop transmitting on this channel.

Some devices are capable of communicating in an ad hoc manner without being attached to a network. Ad hoc devices form a point-to-point communication channel, with one of the devices taking the role of master and, therefore, taking on the requirement for DFS and all of the applicable requirements for a master.

Range and performance 

The radio wavelength in the 5 GHz band is half of the wavelength in the 2.4 GHz band. As a consequence, a radio module using the 5 GHz band will have a narrower range than a radio operating on the 2.4 GHz band using the same output power. How much less the range will be is hard to predict as it depends on the radio conditions at the location in consideration. Further, diverse materials absorb frequencies differently which, in turn, dramatically affects the range. In order to learn the exact range, the solution has to be tested live.

Tests in factories in the 5 GHz band have shown that the range can be between 50 meters to 100 meters in free line-of-sight. Obstacles, interference, materials, and use of large data packages can decrease the range substantially.

Summary 

By using the 5 GHz band for Wireless LAN communication, a number of advantages and cost decreases can be achieved. By adding 23* possible Wireless LAN channels, frequency planning, density (the number of active wireless devices within the radio coverage space) and the installation complexity can be dramatically improved. An extra bonus would be the freeing up of the 2.4 GHz band for other radio technologies.

These advantages, together with increasing availability of 5 GHz industrial products, will increase the use of the 5 GHz band greatly in the near future. Up till now, the use of the 5 GHz band in industrial applications has been more or less limited to products such as smaller access points and small compact clients (based on the same platforms as the access points). Already available on the market are OEM wireless modules for integration in various industrial products as well as serial Wireless LAN clients for integration of smaller devices and existing serial communication based products.

* For FCC channels 120 – 132, use is restricted near airports due to the interference risk of the Terminal Doppler Weather Radar (TDWR). (ref. FCC KDB 443999). Canada requires a restriction on the channels 120 – 128.

 

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Understanding Wi-Fi’s two spectrum bands: 2.4GHz and 5GHz Wi-Fi

5 GHz vs 2.4 GHz Wireless Networks

5GHz networks have been around for many years, utilizing 802.11a standards. 5GHz networks are not as popular as 2.4GHz wireless networks (802.11b or g) however, because 5Ghz equipment has always been more costly to deploy. This has made 2.4GHz networks an easy choice for many users, which in turn has allowed 2.4Ghz networks to become a well established standard.

802.11n standard is growing in popularity and it supports both 2.4 and 5 GHz clients. To get the most performance from 802.11n, 5GHz networks should be considered.

Dual band (5GHz & 2.4GHz) access points and network adapters are available and dual band network cards are already built into many laptops so switching between networks will become easier as time goes on.

See IEEE 802.11 standards for more information on wireless networking standards.

Limitations of 2.4GHz

For many years wireless local area networks have been built utilizing the 2.4GHz frequency. As the number of wireless networks and network users have grown, the limits of 2.4GHz are starting to show. In more densely populated areas with more and more wireless networks, conflicts and interference can develop from the shear amount of traffic, access points, and network cards.

Cell Phones

Another issue with 2.4GHz wireless networks is that the frequency is also used by many cordless phones and microwaves which can cause interference. All of this traffic and interfering signals reduce the speed of a wireless network. The interference can negatively impact users, routers and access points.

To add to the overcrowding of 2.4GHz networks is the newer cell phones, iPhones, BlackBerry and Android phones. They can now access WiFi 2.4GHz networks for Internet browsing. As the number of WiFi enabled phones grows, stress on 2.4GHz networks will grow as well.

Still another issue with 2.4GHz is that it is mostly unregulated so high powered antennas, high powered network cards and access points can negatively affect nearby networks.

5GHz Frequency Networks

5GHz frequency wireless networks can offer a relief from the overcrowding of 2.4GHz. It has a clear signal and more channels that can be combined for higher speeds. 5GHz networks do not suffer the overcrowding that 2.4MHz networks do. Currently 5.4GHz has less traffic through use and it can handle more traffic more efficiently as the frequency gains in popularity. 5GHz operates on a larger spectrum with more non overlapping channels. Each channel has 20MHz of bandwidth which allows for much better speeds compared to 2.5GHz band (the entire 2.4GHz band is only 80MHz wide).

  • Clearer Signal
  • More Non Overlapping Channels
  • Can offer higher speeds

5GHz Network Disadvantages

There are some disadvantages to going to a 5GHz wireless network. One is that the higher the frequency of a wireless signal, the shorter its range. For example, 2.4 GHz networks cover a substantially larger range than 5 GHz wireless networks. 5 GHz networks do not penetrate solid objects such as walls nearly as well as do 2.4 GHz signals. This can limit an access points reach inside buildings like homes and offices where many walls may come between a wireless antenna and the user.

Another disadvantage is that 5GHz equipment does not readily mix with 2.4GHz equipment already installed. This is a consideration if you’re upgrading a current large wireless network  installation. If you wanted to mix an already installed 2.4GHz network with a 5GHz network, you would have to make sure all components of the network is dual band.

Cost is another factor. The popularity of 2.4GHz means that wireless network components such as access points, antennas and network cards are more easily available and costs less.

One perceived advantage of a higher frequency is speed. However, 5GHz networks are not necessarily faster than 2.4GHz. There are 2.4GHz products using 802.11g that can match or can be faster that 5GHz 802.11a by using paired radios inside access points instead of one which can increase capacity up to 108Mbps.

Which Network?

As you can probably see, switching to 5GHz requires planning. There are a few things to consider before making the jump. In general, if high performance and over crowding of other 2.4GHz networks in the area is an important factor, then 5GHz wireless network may be the answer. However, If you have little control of what network cards your users are using or of access points, then a 2.4GHz system may be a better choice.

Dual Band Wireless Networking

Dual band equipment that covers both 2.4GHz and 5GHz is ideal and covers the best of both worlds. If the cost is within your budget, a dual band wireless network should be considered.

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