Unanswered Question
Apr 6th, 2007

Welcome to the Cisco Networking Professionals Ask the Expert conversation. This is an opportunity to get an update on Outdoor Wireless with Cisco expert Fred Niehaus. Fred Niehaus is a technical marketing engineer for the Wireless Networking Business Unit at Cisco Systems, Inc. He has extensive customer contact and is responsible for developing and marketing enterprise class wireless solutions using Cisco Aironet and Airespace Series Wireless LAN products.


Remember to use the rating system to let Fred know if you have received an adequate response.


Fred might not be able to answer each question due to the volume expected during this event. Our moderators will post many of the unanswered questions in other discussion forums shortly after the event. This event lasts through April 20, 2007. Visit this forum often to view responses to your questions and the questions of other community members.

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (11 ratings)
m-geisler Sat, 04/07/2007 - 16:39

Hello Fred!

I am looking into some outdoor mesh with the 1500, and was wondering how can the backhaul reach 1 mile and more. Isn't 802.11a limited to 500feetat6Mbp? (omnidirectional antenna?)

What is the throughput at one mile?



fredn Mon, 04/09/2007 - 05:16

The recommended distances for the Mesh backhaul is typically between 1000 to 4000 Ft as this assumes you are connecting a Root Mesh AP referred to as a "RAP" or Rooftop Access Point to a "MAP" Mesh Access Point (that's usually an AP mounted on say a telephone or street light pole using an Omni antenna).

The backhaul link can certainly go further if you aim the signal in a given direction (using a directional antenna).

However, when doing same, it does limit the options of the AP to "mesh" to only those APs within the area covered by the directional antenna.

abddandashi Mon, 04/09/2007 - 06:04

Dear Sir,

Thank you for your reply, if you may have a link for a Cisco blueprint on Wireless mesh (Aironet 1500) installation, and Aironet 1400 bridge installation.

Do all the MAP (Mesh AP) have to be connected to same or one RAP (Root Mesh AP)?

fredn Mon, 04/09/2007 - 07:43

Please reach out to your Cisco account team for blueprints, and installation guides.

On the second half of the question..

The MAPs (Mesh APs) can connect to different RAP (Root APs). A Root AP is simply an AP that has a wired connection back to the controller, a sort of "anchor point" for the mesh APs to form their mesh around.

You can have multiple RAPs or in some cases (a RAP) can have a "wireless" link back to the controller (using say a 1400 Bridge or a third party product) such as a Redline (WiMax Bridge). But typically the RAP is always directly wired to the controller via Ethernet unless there is a reason to do as I described above.

abddandashi Sun, 04/08/2007 - 07:09


Does the Aironet 1500 behave as a bridge or AP for long distance coverage? (3 to 4 miles), and if it is an AP, how large the cell?



fredn Mon, 04/09/2007 - 05:26

The 1500 series is designed to create a wireless cell for clients typically using 2.4 GHz (802.11b/g). Given most clients do not have an external antenna (their are simply wireless clients built into laptops) the range is limited to roughly 300-500 Ft from the client to the pole (Mesh AP).

Clients can exceed this range if the client is enhanced (using say an external antenna on a vehicle for example). But generally speaking it is short range, the client data is then bridged back to the POP via the integrated 5 GHz (or if public safety 4./9 GHz). This backhaul link (also serves to create the mesh network so recommended distances on the backhaul are typically 1000 to 4000 Ft (this allows the mesh APs to see other mesh APs).

Greater distances can be attained if directional antennas are used on the backhaul links. However if the requirement is a long haul (3-4 mile) Bridge link, you might want to look at products such as the 1300 and 1400 outdoor bridges as these types of longer links typically don't require meshing functionality.

You can also do a hybrid approach (using say the 1400 outdoor Bridge for a longer distance link) and then scale locally with mesh.

soklamarhy Tue, 04/10/2007 - 04:46


Could I use my 1242 AP's as wireless bridges between two buildings? It would be nice to integrate with my current controllers.

If not, how could I make this happen with the 1242 APs?

fredn Tue, 04/10/2007 - 06:12

Yes you can use a pair of 1242 APs in Bridge mode to link between two buildings. Although the 1242 is not "weatherproof" it can certainly be located indoors using an antenna cable to get the antennas outside of the building.

The 1242 AP has many features in automomous mode Bridge, Workgroup Bridge, and in a new update it will also support a new mode called "Universal Workgroup Bridge" where the AP can act like a "wireless shim" for an Ethernet client.

For linking buildings together "Bridge mode" is preferred.

When an AP 1242 is converted to LWAPP mode (unified) it loses Bridge functionality, so for the purposes of linking buildings together I would simply run them as Bridges, in this mode, they will not be seen by a controller.

carlo-lopez Tue, 04/10/2007 - 06:45

I am tasked on deploying Wi-Fi in one of our larger parks and would like to implement WAP that will function as a Bridge and a WAP at the same time. Can you recommend the type of WAP that I can use for this delpoyment that does not need a line of site for the Bridge mode?

fredn Tue, 04/10/2007 - 12:35

Anytime you deploy wireless products that operate at very high frequencies like 2.4 and 5 GHz you really do need line of sight.

Failure to obtain line of sight sets you up for strange RF connection problems, for example I was in Georgia and was able to do a fairly long link through some GA Pine trees but up in Ohio one single maple tree branch completely cut out the signal. Things like this will happen to you without line of sight and it can vary with weather conditions as well (moisture content of trees) etc..

The 1300 Bridge product can also function as an AP, but once you attempt to use directional antennas (it will be much harder for clients to connect to same).

I'd also look at the 1500 mesh product but again line of sight really is required.

ktradmin2 Tue, 04/10/2007 - 14:30


i have a 11000sqft warehouse in which i need to deploy a wireless solution. i have done little research on the Aironet 1240 and would like to have more info if that would be an adequate solution. Any information regarding the model and antenna configurations would be appreciated.

Thank you.

fredn Wed, 04/11/2007 - 16:09

Sure the Aironet 1240 is a fine product for warehouse deployments. Take a look at this URL here

The overall indoor range (using the stock rubber dipole antenna and extended temperatures can be found at this URL:

Further distances can be attained by using external antennas, check out the antenna reference guide at this URL:

The 1240 is used in many warehouse deployments, including some very challenging "football field size freezers".


abddandashi Tue, 04/10/2007 - 21:45

Dear Sir,

My question is not in reference to outdoors wireless, but i really would appreciate your response.

Can I upgrade the AIR-AP1231G-A-K9 into a LWAP to work with AIR-WLC2106-K9? If not, which LWAP would be good for this WLC?

e.g: AIR-LAP1231G-A-K9


carlo-lopez Wed, 04/11/2007 - 05:28

Thank you for your response regarding the 1500's. We have several WAPs installed in various models from 1100, 1200, 1300, 1400 and 1500 series in both outdoor and indoor deployments. Most of them are on different Vlan's located at various facilities. What is your recommendation as far as managing and monitoring these WAP's at a central location?

fredn Fri, 04/20/2007 - 06:50

There are really two different operating systems that you are calling out here stand alone IOS (autonomous) and LWAPP (unified)mode.

The reason there are two different operating systems is because they serve different but similiar purposes.. mainly revolving around "features".

The (unified system) requires a controller and it has some features like rogue AP detection and location based services) that are not really supported with autonomous (stand alone IOS systems).

The Stand alone IOS (autonomous) has the advantage of not requiring a controller and is better for some smaller verticals where perhaps you are not using as many APs and therefore don't need a controller (such as a point to point Bridge link or small office.

For managing (unified LWAPP systems) I'd suggest using WCS see this URL:

For larger IOS (autonomous) based systems, the management utility is WLSE see this URL:

fredn Wed, 04/11/2007 - 16:13

1200 series APs that contain the 802.11g radio (not the older .11b radio) can be upgraded simply by loading new firmware to work in a unified (LWAPP) mode. If the 1200 series AP has a 5 GHz radio (it must also be one of the newer radios (white serpentine stripe or support external antenna connectors). The older black stripe (serpentine) 5 GHz radio and/or the older 802.11b only radio is not supported within the unified (LWAPP) code.

Given your unit has an 802.11g radio I see no issues or problem with upgrading it to unified.

fredn Fri, 04/20/2007 - 05:51

Yes you can upgrade your AIR-AP1231G-A-K9 autonomous AP to LWAPP. Any 1200 series AP with a .11g radio can support LWAPP.

As a side note, the older 1200 series AP with the .11b only radio (350 series) can also be upgraded to LWAPP but before you do this, you must remove the old .11b radio and upgrad to a .11g radio first before going to the LWAPP image.


My company is being asked to provide outdoor public and private wireless coverage at an increasing rate. One of the biggest problems with the 1500 mesh solution is in the site survey and cost estimates. Can the 1500 AP be used in a site survey mode? Most customers want to know a fixed cost when delpoying any system and with wireless, it is difficult to be accurate because of field conditions that always appear. If the project is underbid because some unknown condition exists, then the costs usually have to be absorbed by the installing company. Do you know of any way to mitigate these problems and provide more accurate deployment estimates? Thanks

fredn Thu, 04/12/2007 - 11:25

Well generally (assuming you have line of sight) the AP placement distance is as follows...

Root AP to Mesh AP 1000-4000 Ft

Mesh AP to Mesh AP 500-1000 Ft

Client to Mesh AP 300-500 Ft

While you can do some surveys with the 1500 (client connectivity) performing a backhaul survey can be done using WCS or simply looking at the link from the controller.

As far as estimating number of APs, there are third party RF prediction tools from folks like and

Also, Cisco has training for customers who become a Cisco Advanced Technology Partner.

Hi Fred,

I have a new location coming online and it is close to a location that has a fiber connection back to our central hub. Wireless is being considered to do this...however, is that recommeded for VOIP? We have two call managers at the central office so it will have to travel from the new location over the wireless and through the fiber back to the central location... Is this feasible?


fredn Mon, 04/16/2007 - 08:02

Is outdoor wireless links recommended for VOIP is I suppose the real question here. Yes I think it is provided you understand the caveots with deploying same. Given WiFi is an unlicensed technology, and anyone may use the frequencies, it is susceptible to interference. When deploying wireless indoors (you pretty much own the RF environment) as signals rarely travel far outside your "windows" and the amount of interference penetrating your building is also small.

When doing an outdoor link, the antenna is outside (free to pick up signals from other sources) and if those sources are powerful (say the guy next door is running a Wireless ISP on those channels, or perhaps a nearby person with a "slingbox" type device is sharing his cable TV with his friend down the street... in those specific cases the quality of your connection could be effected regardless if QoS or CAC is enabled on the device.

Although the chances are real good that you would not encounter interference and that such a link would work well, perhaps for years without an interference issue.

I believe that if you are using outdoor VOIP for emergency traffic, or if this link must remain up (at all times) then perhaps it is better to consider Wireless as a great "backup" link, or I would consider adding redundancy to the system with another wireless link on a different channel or perhaps have a fail-over to a more costly alternative such as a wired (subscriber based) system.

I would be hesitant to recommend an outdoor WiFi link as the main conduit for emergency VOIP traffic without a fall-back technology, such as another wireless backup link or wired fail-over.

abuera Fri, 04/13/2007 - 03:03

Hi Frank,

My customer needs an outdoor wireless solution for a 2km Funicular environment.

I was thinking of a 1300 Aironet solution with an AP mode for the fixed installed equipments along the railway and a workgroup mode for the in-vehicle equipments that would be connected to the CCTV cameras.

What do you recommend?

Thank you in advance.

fredn Mon, 04/16/2007 - 08:07

1300 AP, or a 1500 Mesh AP, (or even a 1240 in a NEMA enclosure) are all "fair game" for such a deployment (which one to use depends on the size and logistics of the deployment I suppose). 1300s would work fine and you could use a 1240 in the vehicle (using WGB mode). CCTV cameras should be the "smart kind" meaning they should be Ethernet friendly and consume bandwidth needlessly like analog cameras typically do.

azazello_cisco Wed, 04/18/2007 - 21:47

Hi Fred,

I've got a general question about outdoor wireless. As you might know, some small cities in the USA are almost totally covered with wireless. How is that achieved? I mean, are there any special equipment or special protocols, not a,b or g? Please tell me more about it and if possible provide with some useful links.

Thank you very much in advance

fredn Thu, 04/19/2007 - 09:04

There are many ways to "blanket a city" with wireless, a very common approach is to use the Cisco 1500 outdoor mesh solution at this URL for an overview, I'd recommend then watching the Dayton Ohio deployment video.

The way it is typically done is like this....

A RAP (Root Access Point) is placed at a good location, say on top of a large building that overlooks an area of the city or town.

This RAP unit has a wired connection back to the controller and establishes a wireless link to another AP (referred to as a MAP or "Mesh Access Point") using 5 GHz or if public safety perhaps 4.9 GHz.

These MAP devices are located in the area of the users typically atop street lights (using the photocell pass through adapter on the light) to attain power for the MAP. MAPs then link to other MAPs and "find their way through the mesh" to a RAP that puts them back on the network.

The network is then scaled out by using many RAPs and MAPs. Mostly this is done with 802.11a/b/g type radios.

However, when there is a requirement for non 802.11a/b/g wireless links then in some cases a Cisco CTDP (Certified Technology Developer Partner) is used, for example, Redline Communications may be a good fit when there is a requirement for say a WiMax link.

azazello_cisco Thu, 04/19/2007 - 11:15

Thanks Fred, your reply was extremely useful for me. I have some more questions regarding this topic:

1. The a,b and g standards have a limitation of 100m, I guess that means that i have to deploy MAP-s in every 100m. How real is to cover whole city with that? Maybe Aironet 1500 can reach distances more than 100m?

2. What's the maximum(recommended) number of MAPs I can deploy between two neighboring RAPs?

3. Will this wireless mesh interference with possibly existing wireless signals penetrating out of the nearest buildings(indoor Wireless LANs) placed in radius of 100meters?

4. Will this wireless mesh reach any offices in neighboring buildings?

Thank you once more,


fredn Fri, 04/20/2007 - 07:03

Well the issue of client distance has to do with the client. Most clients (laptops) have an antenna that is buried inside the laptop and it is of very little gain. That is the real limiting factor here in distances ending up approx 300-500 Ft. If your client has an external antenna (say mounted on top of a vehicle) then range can much further.

As far as covering an entire city, although this can be done, generally folks start out covering "key areas" and then expand to other areas and the need for coverage in those areas increase. WiFi uses a very low power typically around 100-500 mW (a typical "walkie talkie" is 5000 mW (or 5 Watts) the reason WiFi power is so low is to permit it's wide spread use without causing severe interference to others. It's that requirement that drives the need for additional units, and why each unit creates a "small" cell.

Maximum number of MAPs is really a factor of the radio bandwidth available, while you can create very high dense deployments of MAPs you'll want to add additional RAPs to properly manage the flow of data.

Take a look at this URL that specifically talks about the 1500 (and there is an archived 1500 mesh discussion).

There is also a Cisco Mesh deployment guide that should also help answer many of these questions.

Wireless mesh can reach nearby offices if those offices have CPE (customer Premisis Equipment devices) meaning wireless Bridges or other devices. Usually a laptop within a building has too weak of a signal to hit the mesh unless the operator happens to be near a window.

sakthicisco Mon, 04/16/2007 - 01:07

Hi Fred,

I hav got 3 questions to ask u.I need guidance in outdoor wireless networking.

my project has both multiple base station and pt to pt base stations

1)Does Access point is similar to base station?

2)How can we diffrentiate Access point from Bridge function?

3)Can i use Aironet 1300 series,interconnecting 20 buildings in an area A1 which includes pt to pt and multi pt bridiging?

Awaiting for ur reply

fredn Mon, 04/16/2007 - 08:11

1. Some folks refer to APs as base stations. The role of an Access Point is to simply provide connectivity to wireless clients and put their signals onto the wired segment.

2. The purpose of a Bridge is to link wired segments to wired segments. The purpose of an AP I've defined. Some AP's have Bridge functionality (Cisco-Aironet APs certainly do).

3. Start out doing outdoor Bridging SLOWLY, get a few buildings linked and get your feet wet, don't just run out and buy for 20 buildings. There are challenges such as line of sight, and antenna mounting requirements. Yes I believe you can link that many buildings but please work with a Cisco account team to help you scale this properly.

kevinbaum Mon, 04/16/2007 - 04:43

Hello Fred,

I need to set up a wireless network between two buildings. What would you recomend for equipment to use. The buildings are about 500 ft apart. I have tried the linksys WAP,s but lost signal half way between the buildings. Could you please advise me on a solution?

fredn Mon, 04/16/2007 - 08:16

If the buildings are only 500 Ft apart, you could use the BR1300 series Bridge for 2.4 GHz or the BR1400 series Bridge using the less congested 5 GHz band.

Either product would work well.

Another option (if you can locate the AP indoors) and simply run the antenna cable outdoors might be to use a pair of AP1240's in Bridge mode.

Any of these three options would work fine, given the buildings are that close 500 Ft and I assume you have line of sight, the only advantage to using the AP1240 would be that you could use two sets of antennas (one on 2.4 GHz and one on 5 GHz) at each site, that way if you did encounter interference you could "software switch" between bands and you would have some redundancy should an antenna happen to get damaged or a cable cut.

ragnar_anfinsen Mon, 04/16/2007 - 23:48

Hi Fred.

I have been tasked to find the recommended specs on building VoIP over WiFi in an outdoor city environment.

Do Cisco have any recommended guidelines for this kind of deployment?

What do you suggest the distances should be between AP's, including Mesh technology?

When doing sitesurvey, what RSSI threshold should we stay above to have a good VoIP link?

Best Regards

Ragnar Anfinsen

fredn Fri, 04/20/2007 - 05:56

Please take a look at a previous post I've answered regarding outdoor VoIP applications. Distances between Mesh AP's were also defined in a previous post but to recap, distances from the ROOT AP (RAP) to Mesh APs (MAPS) is 1000-4000 Ft with distances between MAP to MAP around 500-1000 Ft (this is because the MAPs are lower to the ground) and client distance from MAP for 2.4 GHz access is roughly 300-500 Ft (further if external antenna is used on the client). RSSI thresholds while very important (you also need to look at how many "RF HOPS" the mesh is doing, as well as the backhaul mesh link and the 2.4 GHz client link.. (there is not one specific value), however there are design guides for indoor VoIP that may be helpful (see your Cisco account team for this) and other design help.

sakthicisco Tue, 04/17/2007 - 00:42

hai fred

1)What is the diff between autonomous mode and unified network mode in 1310 series?

2)can a 1310 series in autonomous AP mode provide bridging,report IDS event,support 802.3af PoE,17dBi gain?

3)can a 3560 catalyst act as WLAN switch?

Thank u in advance..

fredn Fri, 04/20/2007 - 06:05

When discussing the 1310 series outdoor Bridge product, the autonomous mode allows the AP to work as a Bridge (typically used to Bridge building to building traffic). In this mode a controller is not used. In the unified mode, the 1310 is no longer a Bridge but rather a rugged robust outdoor Access Point, in this mode the 1310 primarily services clients and is fully managed by the unified controller. It's really just two different modes (in autonomous it's a Bridge) in Unified it's a rugged AP.

Yes a 1310 in autonomous mode can provide Bridging, IDS events (and other non-Bridging functions only happen with the device is a unified AP). It does support 17 dBi antennas and rather then 802.3af, it supports a unique method of PoE that is better for outdoor usage, it injects power over the two RG-6 coaxial cables, this allows both Ethernet and power to travel to the 1310 and at the same time allow for proper grounding and lightning protection of same. A 3560 is not a WLAN switch per-se (you still need a controller) if you are running the 1310 in unified (LWAPP) mode.

clark.ambrose Tue, 04/17/2007 - 12:35

Hello Fred:

Similar to a previous posting I have to recommend and implement a wireless connection between two buildings, however, these buildings are only about 200 feet apart and I have window or roof access in each building in a direct line of sight with no obstructions between them.

I believe I can install indoor APs in bridged mode, but I am not sure whether I will need an external antenna or not. The Aironet 1100 claims outdoor range of up to 225 feet at 36Mbps.

If I move up to the 1200 series, what size antenna would you recommend? The APs would likely be mounted within 1-2m of the antenna.

When I have been in the area I have detected no other wireless networks.

fredn Fri, 04/20/2007 - 06:12

When Bridging across small distances such as 200 Ft many times simply placing the AP in the window may be all that's required. TRY IT and see.

Keep in mind some glass has "tinting" properties so signals going through the glass may be reduced by 3-5 dB or more depending on the number of panes of glass and if there is any conductive gas being used in the window and if the window is grounded.

The best antenna for putting in a window for this kind of a link would be a patch antenna since the patch antenna is flat and can be taped or secured to the window easily. I'd recommend a 6 dBi patch antenna Cisco AIR-ANT2460P-R if using 2.4 GHz. If using 5 GHz then use the AIR-ANT5170P-R.

For a complete list of antennas available, check out the antenna reference guide at this URL:

advantexpix Wed, 04/18/2007 - 05:59

Hi Fred I was wondering if you could help. I have 4 x 1242 AP's setup as two seperate bridges. I'm looking to setup either load balancing between the two or just general link redundancy. what you suggest i do for this?

khof Thu, 04/19/2007 - 00:25

Hi Fred,

I have two buildings connected with 2 x AP1231 in bridge mode. Now I have to trunk several VLANs between the bulding. Is this possible with this APs and do you have a link with an config example?

Thanx, Frank

fredn Fri, 04/20/2007 - 06:39

The Access Points are running in Bridge mode at (layer 2) although it will pass the VLAN tags the Bridge will not perform any processing on same. You will need to handle this on the network side.

Take a look at the deployment guide at this URL, it should help you (BTW) when looking for information (check out the related product documentation) for example 1300 and 1400 Bridge product as all these devices run Cisco IOS so they make good reference material and sometimes address topics that perhaps the 1231 does not since the 1231 was not specifically designed for Bridging (that just happens to be a feature it supports).

See this URL for more..

fredn Fri, 04/20/2007 - 12:14

The Access Points are running in Bridge mode at (layer 2) although it will pass the VLAN tags the Bridge will not perform any processing on same. You will need to handle this on the network side.

Take a look at the deployment guide at this URL, it should help you (BTW) when looking for information (check out the related product documentation) for example 1300 and 1400 Bridge product as all these devices run Cisco IOS so they make good reference material and sometimes address topics that perhaps the 1231 does not since the 1231 was not specifically designed for Bridging (that just happens to be a feature it supports).

See this URL for more..

fredn Fri, 04/20/2007 - 06:26

You would really need to address this within the (network infrastructure) the Bridge is a layer 2 device so it can't manage different Bridge links for the purpose of load balancing. This is no different then a WLAN Bridge link and say a T-1 and trying to balance between same.

Suggest using PAgP for information on how to set this up on a Cisco Bridge link see the 1400 deployment guide at this URL.

fredn Fri, 04/20/2007 - 12:13

You would really need to address this within the (network infrastructure) the Bridge is a layer 2 device so it can't manage different Bridge links for the purpose of load balancing. This is no different then a WLAN Bridge link and say a T-1 and trying to balance between same.

Suggest using PAgP for information on how to set this up on a Cisco Bridge link see the 1400 deployment guide at this URL.

jojsanto Tue, 09/07/2010 - 10:05

Hi Team,

Can anyone help me out with the BR1400? Is there a solution that can let us have a range in point-to-multipoint of more than 30km? I am voting to NO, but I believe it is better if experts can say something about it.

Thanks in advance.



This Discussion



Trending Topics: Other Wireless Mobility

client could not be authenticated
Network Analysis Module (NAM) Products
Cisco 6500 nam
reason 440 driver failure
Cisco password cracker
Cisco Wireless mode