Wireless network Mixed Mode deployments

[M.Jallad]

Hi Guys,

Any ideas about drawbacks or performance issues that may appear when adding wireless Access Points supporting (802.11g/n) near other existing AP's supporting only legacy dual channels  (802.11a/b/g). Especially on wireless end users that is operating on existing legacy AP's (some end users may have 802.11g/n antennas others may only have 802.11g antennas).

Any help would be appreciated,

[Leo Laohoo]

The main drawback when deploying only 802.11b/g are channel interferrence.

You need to determine if your neighbors have active 802.11b/g radios and how strong are they.  Next, you need to look INSIDE your premises.  Bluetooth, microwave ovens, wireless fire alarms use 802.11b.

An AP that supports CleanAir and WLC would be beneficial because with CleanAir, the AP can identify the channel interferrence and change channels accordingly, however, the latest generation of CleanAir APs (3500, 1600, 2600, 3600) have dual radios.  There are no single-radio AP that supports CleanAir.

[M.Jallad]

Hi leolaohoo,

I'm asking about the effect of deploying AP's supporting 802.11g/n (for example i was thinking of Cisco 1040 AP which by the way doesn't support CleanAir) on the same WLAN that actually contains Other AP's supporting only legacy 802.11a/g ; of course the purpose of adding more AP's is to provide for the increasing number of WLAN users in the same covered area and maybe preparing to fully support both legacy and 802.11n clients using maximum throughput client can attain.

My concern is that having such a mixed environment may affect simple WLAN operations such as roaming between AP's of different types, throughput, and for sure interference as you've explained.

Thanks,

[Leo Laohoo]

My concern is that having such a mixed environment may affect simple WLAN operations such as roaming between AP's of different types, throughput, and for sure interference as you've explained.

Deploying APs in a mixed 802.11a and 802.11b is common.  But deploying single radio APs in multi-band environment doesn't make any sense.

Roaming will no get affected when roaming from an AP that supports only 802.11b/g and an AP that supports 802.11 a/b/g if the client only supports 802.11 b.

The only issue you'll see, in theory, is when you have a client that only supports 802.11 a/n.  And take note I said "in theory" because, by default all clients will support 802.11 b/g.  The only time you'll see a client not supporting 802.11 a/n is when someone has disabled this on the wireless NIC or someone's bought a client that only supports 802.11 b/g.

Now, I really do not understand why you want to deploy only 802.11b/g when the chances of you getting channel interferrence increases exponentially.  In alot of environments (including mine), I have DISABLED the data rates from 1 Mbps to 12 Mbps rendering 802.11b not supported.

[M.Jallad]

Deploying APs in a mixed 802.11a and 802.11b is common.  But deploying single radio APs in multi-band environment doesn't make any sense. 
     

I'm already utilizing only the 2.4 GHz band anyway (the other band is not licensed in jordan because it is reserved), so i guess it make sense adding new AP's with single band 2.4GHz support getting a better price than dual banded AP's without really utilizing 5 GHz band.

Roaming will no get affected when roaming from an AP that supports only 802.11b/g and an AP that supports 802.11 a/b/g if the client only supports 802.11 b. 

As i have written above and modifying your statement; would roaming get affected if it occured for example between AP supporting 802.11g (1131G) and another supporting 802.11g/n (1041N).

Now, I really do not understand why you want to deploy only 802.11b/g when the chances of you getting channel interferrence increases exponentially.  In alot of environments (including mine), I have DISABLED the data rates from 1 Mbps to 12 Mbps rendering 802.11b not supported.

Just Forget about 802.11b; i'm discussing the compatability between 802.11n and 802.11g and how they could coexist and utilized in the same system without losing throughput especially clients connecting to 802.11g/n and utilizing n data rates.

[Leo Laohoo]

As i have written above and modifying your statement; would roaming get affected if it occured for example between AP supporting 802.11g (1131G) and another supporting 802.11g/n (1041N).

Roaming will depend if you have, for example, wireless overlap.  If you have adequate overlap of wireless, ideal at 20%, then a client can roam from one wireless cell to another seamlessly.

Just Forget about 802.11b; i'm discussing the compatability between 802.11n and 802.11g and how they could coexist and utilized in the same system without losing throughput especially clients connecting to 802.11g/n and utilizing n data rates.

Won't make any difference and won't work.  802.11n requires you to channel-bond 802.11a radio.  Cisco Aironet will NOT support channel bonding of 802.11b because it doesn't make any technical sense.  So if your AP doesn't have 802.11a then you can't run 802.11n.

[M.Jallad]

Won't make any difference and won't work.  802.11n requires you to channel-bond 802.11a radio.  Cisco Aironet will NOT support channel bonding of 802.11b because it doesn't make any technical sense.  So if your AP doesn't have 802.11a then you can't run 802.11n.

what about this part number : AIR-LAP1041N-E-K9: Single-band Controller-based 802.11g/n , it is a single band 2.4GHz AP and doesn't have 5GHz antenna however it supports 802.11n standard datarates.

My question can be as simple as this  : would this accesspoint "AIR-LAP1041N-E-K9" support 802.11G and 802.11N clients simultaneously.

Thanks,

[Leo Laohoo]

1.  On 02 April 2013, Cisco announced the End-of-Sale of the AP1040.

2.  I have not played with an AP with a single radio, however, I will still maintain my opinion that you will NOT be able to enable 802.11n on a 802.11b.  So to answer your question, the answer is NO.  You can only allow 802.11b/g clients to connect on this AP.