As many enterprises look to deploy wireless voice they need to make an important decision regarding the band on which to roll out this service. The simplest approach would be to just deploy voice on their existing 2.4GHz 802.11b/g/n data network. They should, however, take a serious look at the option of a voice overlay on the 5 GHz 802.11a/n network. If the enterprise has installed dual mode radios in preparation for voice, then they have already made the strategic decision to separate voice and data and avoid the 2.4GHz Naughty list.
What is on this 2.4GHz Naughty list?
The top reason on this list is the well known problem of interference. But the issue of interference is much more mischievous than the standard example of microwave ovens. Interference comes in many shapes and sizes - just like the many reasons naughty children make the dreaded list of the big guy in the red suit. This is a long list and here are some of the common causes of interference at 2.4GHz:
Microwave ovens in break rooms and office areas found in organizations of all industries – the noise floor will rise drastically depending on vicinity. Also it is intermittent which makes it harder to diagnose.
Wireless Thermostat controls (Wi-Fi & Zigbee networks) found in pharmacies, grocery stores, and Distribution Centers
Security Systems (Alarm systems, Wireless video cameras) found in organizations of all industries
Smart TV, Gaming system found in retail
Garage door openers
Adjacent stores Wi-Fi networks
Cordless phones
Proprietary networks found in theme parks and cruise lines
Why are there so many competing technologies at the 2.4GHz band?
Because it’s unlicensed and radios in this band have become a commodity. Another flavor of Interference to look out for that is inherent to 802.11 at 2.4GHz: adjacent channel(s) interference. There are ways to mitigate this but you are limited to what you can do:
Only channels 1,6,11 are relatively available for use which limits capacity and reuse patterns
Channels 4 and 11 can also be used at 10% increase in interference which may be mitigated by choices of adjacent channels
Bluetooth also operates in the 2.4GHz band and can cause issues with voice:
Bluetooth operation within same band will consume bandwidth
Bluetooth headset operation can consume significant bandwidth which may interfere with other handsets co-located on a different 802.11b/g channel
Another naughty item on the list are legacy 802.11b devices which don’t play well with others and as a result lower the effective bandwidth for all devices in the 2.4GHz band.
The cumulative effect of the “Naughties” (OK, I made up this word, but it works, right?) on running voice in 2.4GHz are
Poor audio quality
Jitter
Choppy audio
Audio gaps
Dropped calls
Slower roam times which could also lead to dropped calls
Lower capacity with 802.11b devices in the environment (54MB bandwidth derated to 11MB)
Fewer channels therefore less capacity (user density)
How can I avoid this long list of “Naughties” so I don’t get a lump of coal in my stocking from irate users?
A best practice is to deploy voice on the 5GHz band and leave all your data devices on 2.4GHz as data services are more resilient to the effects of the “Naughties”.
If there’s a “Naughty” list, then there must be a “Nice” list for running voice on the 5GHz band, right?
Absolutely, here is the Nice list…
Even though 5GHz is also unlicensed, its general adoption rate is much lower therefore you have fewer devices/clients competing for bandwidth (sort of like an all you can eat buffet…maybe that is how Santa got so big)
You go from 3 non-overlapping channels to 23 non-overlapping channels in the United States (more channels are available internationally but it varies by country)
Significantly lower noise floor (retail -84dB at 2.4GHz but -95dB at 5GHz)
Future proofing for additional voice traffic and new services
802.11ac is backward compatible with 802.11a
Longer effective lifespan of 802.11a devices because of compatibility with 802.11ac
Increases capacity/user density voice
Better co-existence with future high bandwidth services video, analytics, support ability to
Simultaneously communicate with multiple devices for higher capacity, throughput/bandwidth therefore reduce likelihood for poor audio call quality (jitter, packet loss, etc)
To “wrap up,” if your enterprise is thinking about rolling out voice, take a serious look at dual band APs so you can put voice on 5GHz and avoid the Naughty List. It’s so much better to be on the Nice list!
Happy Holidays!
Mike Frank is a Professional Services Release Management Consultant for Motorola Solutions. He would like to acknowledge the contributions of Santa’s helper Kris Hobbs, Enterprise Solutions Specialist II, Motorola Solutions to this blog.
This is great, I was kept interested with the analogies made! I would like to add in that the "nice" list should also include the benefit of having smaller antennas at 5GHz.
Entries » Blog » ‘Tis the Season to Deploy Voice, So Make Sure You Avoid the 2.4GHz Naughty List!
‘Tis the Season to Deploy Voice, So Make Sure You Avoid the 2.4GHz Naughty List!
As many enterprises look to deploy wireless voice they need to make an important decision regarding the band on which to roll out this service. The simplest approach would be to just deploy voice on their existing 2.4GHz 802.11b/g/n data network. They should, however, take a serious look at the option of a voice overlay on the 5 GHz 802.11a/n network. If the enterprise has installed dual mode radios in preparation for voice, then they have already made the strategic decision to separate voice and data and avoid the 2.4GHz Naughty list.
What is on this 2.4GHz Naughty list?
The top reason on this list is the well known problem of interference. But the issue of interference is much more mischievous than the standard example of microwave ovens. Interference comes in many shapes and sizes - just like the many reasons naughty children make the dreaded list of the big guy in the red suit. This is a long list and here are some of the common causes of interference at 2.4GHz:
Why are there so many competing technologies at the 2.4GHz band?
Because it’s unlicensed and radios in this band have become a commodity. Another flavor of Interference to look out for that is inherent to 802.11 at 2.4GHz: adjacent channel(s) interference. There are ways to mitigate this but you are limited to what you can do:
Bluetooth also operates in the 2.4GHz band and can cause issues with voice:
Another naughty item on the list are legacy 802.11b devices which don’t play well with others and as a result lower the effective bandwidth for all devices in the 2.4GHz band.
The cumulative effect of the “Naughties” (OK, I made up this word, but it works, right?) on running voice in 2.4GHz are
How can I avoid this long list of “Naughties” so I don’t get a lump of coal in my stocking from irate users?
A best practice is to deploy voice on the 5GHz band and leave all your data devices on 2.4GHz as data services are more resilient to the effects of the “Naughties”.
If there’s a “Naughty” list, then there must be a “Nice” list for running voice on the 5GHz band, right?
Absolutely, here is the Nice list…
To “wrap up,” if your enterprise is thinking about rolling out voice, take a serious look at dual band APs so you can put voice on 5GHz and avoid the Naughty List. It’s so much better to be on the Nice list!
Happy Holidays!
Mike Frank is a Professional Services Release Management Consultant for Motorola Solutions. He would like to acknowledge the contributions of Santa’s helper Kris Hobbs, Enterprise Solutions Specialist II, Motorola Solutions to this blog.
Learn more about voice readiness assessments.
This is great, I was kept interested with the analogies made! I would like to add in that the "nice" list should also include the benefit of having smaller antennas at 5GHz.