Wireless Access

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Regular Contributor I
Posts: 204
Registered: ‎09-28-2010

Band steering or something else?

I have situations where my wireless deployments are moving from a cubicle/office environment to more of an open, lounge-type area.  Coupling that with the explosion of BYOD, I'm running into problems with APs becoming "overloaded."  It isn't unusual to see 20 clients connected to a single AP.

 

My current deployment is AP93 (2.4GHz).  

 

Since quite a few of the clients are iPads and other Apple and/or dual-band capable devices, would I be better served to look at replacing with AP105 and using band steering?  Or would it be better to add additional APs and use load balancing?

 

My main complaints are coming from an area that is in an already crowded 2.4GHz spectrum, so I'm not sure that adding additional APs and balancing is the best.

 

The space is 2 floors - approx 100' x 100'.   I'm currently covering it with 4 APs, and just walking around the area, coverage is pretty good, problem is the high concentration of users in certain areas.

 

I guess my question is this - according to post below, it isn't a good idea to mix single and dual-band APs.  Pricing wise I guess there isn't much difference between deploying 2 AP93s or 1 AP105....unless I factor in cost of PoE adapters.  Another limitation may be that the local controller (620) is limited to 8 APs.

 

Also, band steering has to be turned on in the VAP profile.  From the previous thread it was asked if turning that on would cause problems with single band APs, but the only response was to try and not mix AP in the same area.......so I'm not clear if enabling band steering would cause any problems - I'm currently running 100% of my deployment on these single band AP93, so we never discussed this option of band steering during our design phase.

 

[quote]

Re: Band Steering[ New ]

NightShade1 wrote:

so for what you told me i can safely turn on band steering and there will be no issue even if i got some APs of single band?

 

Second question is if i got voip over wireless for what you said up i should turn this off

Would it be okay to turn on then the spectrum load balancer? if i got  wireless VOIP

 

 


There should be no issue, but try not to mix and match single and dual band APs in the same area.

 

Most VOIP wireless phones are only deployed in a single band at a time, so you should not have to worry about this.

 

Spectrum Load Balancing is off and you should leave it there unless advised by TAC.[/quote]

Guru Elite
Posts: 20,821
Registered: ‎03-29-2007

Re: Band steering or something else?

[ Edited ]

Adding more 2.4ghz devices will not add more CAPACITY, it will likely add more interference which will DECREASE capacity.  All IPADS are 5ghz capable so adding 5ghz will add capacity for every AP you add, because it has more channels that will not interfere with each other.

 

Band Steering and Spectrum Load Balancing and Local Probe Response Threshold are features that are designed to improve performance in a suboptimal situation.  You should first design based on physics, meaning capacity of the medium and devices and you should not even have Band Steering or Spectrum Load Balancing in mind, because those features are not better than a good RF design.

 

With that being said, in this age of mobility, Capacity through available Channels is King.  Nobody who will be relying on wireless for Capacity should ever purchase single radio APs because wireless usage never goes down:  It always goes up, and capacity will be required.  Always plan a good design, purchase dual radio APs, and you will eliminate alot of headaches.

 

Introduce the new APs and leave band steering and load balancing features off and see what happens.

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Regular Contributor I
Posts: 204
Registered: ‎09-28-2010

Re: Band steering or something else?

Thanks.

 

Initial wireless deployment (Cisco, back in 2001-2002) was with the "wireless as a luxury" mindset.  We also have offices with many "open" cubicle areas - wireless installs were designed to provide access to those users with the expectation that all users in an office would have wired drops.

 

When we switched to Aruba 3 years ago, I suggested that we plan for more usage and better coverage, but the decision makers were adamant that we were doing a "1 for 1" replacement.  As we had never deployed 5GHz in our previous model, that also wasn't an option (we did get some for our main headquarters, but nothing for our remote sites).  I do agree with you in regards to capacity.  I gave my opinion on the new design, but I don't control the purse strings......so I work with what they give me ;)

 

Now fast forward to the iPad (and other tablets) and the explosion of BYOD, and I find myself spending half my time working out better placement and new installs.

 

This one site is what is confusing for me, as they have now shifted to more of a coffee shop/lounge design, which is going to concentrate more users in one particular area instead of previously being spend out in typical cubicle/desk space.

 

Add to that this location is in a downtown area - I count more than 30 nearby networks, most in the 2.4GHz spectrum, thus my hesitation to add another AP93.

 

I do have one extra AP105 laying around, and since most clients are iPad, I thought dual-band would be a logical choice.  I'm also currently waiting on budget allowances to see what I have to work with.

 

I do monitor connections with Airwave and get alerts for APs with more than 15 connections (for more than 15 minutes).  I currently only have 2 or 3 offices that have this problem on a consistent basis.  Unfortunately for me, this "problem" office is our largest and most profitable, so I need to get them right.

 

As I go through and audit each branch office, realistically I'd like to double our AP count (currently 330+).  Will adding AP105 along with the existing AP93 deployment cause any problems?

 

If I do deploy an AP105 to that location, do I need to worry about band steering?  Will the 5GHz-capable clients automatically connect, or would they still prefer the 2.4GHz spectrum? 

 

Looking forward, how much longer before we start seeing 802.11ac in production?  I've already been asked about it several times, and I know it still isn't ratified, but is getting close.

Guru Elite
Posts: 20,821
Registered: ‎03-29-2007

Re: Band steering or something else?

Let's talk some facts:

 

- Just seeing alot of access points does not mean there will be severe interference.  If that interferring access point is not between your users and their access points, it is less likely that their transmissions will collide and have to retransmit, making throughput plunge.  

- Even if you see alot of access points, they also would need to be sending out traffic at a particular bandwidth to start interrupting traffic with your users, especially if it is at 100/200 feet, through a wall, etc.

- Number of users on an access point should not be confused with Utilization of Spectrum.  There are quite a few college Campuses where we see 50 to 75 users on an access point and they are using well-behaved applications like email and Web and they are fine.  There are also users that are attached and they do nothing. It is the Channel Utilization that we should be focused on.

- If your company wants a premium experience or has high-bandwidth requirements, you should not even give them the option to purchase a single-radio AP, because even though it would suffice today, it would not meet their requirements tomorrow.

- Do not worry about Band Steering.  Many clients not only measure signal strength, they also measure signal quality and make the right decision.  Make more spectrum available to them, and you won't even have to think about Band Steering.  

- If you do deploy an AP105, use 20 mhz channels on the A-Band so you can leverage channel reuse for less contention in areas where you have to deploy more than 3 APs.

- Client Support drives standards.  If you do not see any supportable, stable enterprise client support, my advice is to hold off until you do.  802.11ACs full potential will only be realized in the most favorable of circumstances.

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Regular Contributor I
Posts: 204
Registered: ‎09-28-2010

Re: Band steering or something else?

I guess part of my confusion with band steering is from reading the Hotspot deployment:

 

[quote]

Band Selection and Band Steering

It is important to deploy APs capable of both 2.4 GHz and 5 GHz. Many of the new client devices support both 2.4 GHz and 5 GHz operation. When Aruba’s Band Steering feature is enabled, clients that may be operating in 2.4 GHz but that are capable of 5 GHz operation are encouraged to move into the 5 GHz spectrum where there is more capacity.[/quote]

 

I guess what you are saying is the clients will (should) do this on their own.  IF they don't, THEN we can look at enabling/enforcing band steering on the VAP.

 

Okay, so I'm taking it that the AP105 is what I should be looking at? (since that is my only option at this point - I have 1 sitting around, or a bunch of AP93).  I'll swap out the existing AP93 with an AP105 and see if it makes a difference.  At least the site will see something being done!

 

I understand the dual-band/single-band issue.  3 years ago we came up with the design and solution with Aruba - given our requirements and budget contraints, the AP93 was deemed the appropriate solution.  Things change.  I'll do everything I can to stress to management that we NEED dual-band from now on....especially with talk of pushing voice and video to the network.

 

 

I appreciate the advice and knowledge sharing.  While I may be the company's wireless "expert", I'm far from an expert on wireless.  And even though wireless is solely my responsibility, it is not my sole responsibility. 

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