DAS? (distributed antennas)

[RedRyder]

Where can i find out more about distributed antenna systems (DAS)?
Where and who mainly uses them?
Who are the key vendors?
Pros and cons?
etc.

[TelcomJunkie]

Originally Posted by RedRyder

Where can i find out more about distributed antenna systems (DAS)?

The manufactures and one of the few books out there on the topic.

Originally Posted by RedRyder

Where and who mainly uses them?

All of the major carriers utilize them in tough to cover locations. Typically cities with tough zoning, locations with greatly varying terrain (ie. canyons), convention centers, customer sites with large user bases and locations where there isn't enough traffic to warrant installing a regular macro cell.

Originally Posted by RedRyder

Who are the key vendors?

ADC, Andrew, Ericcson/Nokia, Alcatel-Lucent, Juni and LGC Wireless are the main ones I see.

Originally Posted by RedRyder

Pros and cons?
etc.

Quick to install and easy to deploy in tough locations. Zoning and permitting is easy and sometimes not needed. Can be used over a number of mediums like copper or fiber optic depending on vendor.

[RJB]

Originally Posted by TelcomJunkie

The manufactures and one of the few books out there on the topic.


All of the major carriers utilize them in tough to cover locations. Typically cities with tough zoning, locations with greatly varying terrain (ie. canyons), convention centers, customer sites with large user bases and locations where there isn't enough traffic to warrant installing a regular macro cell.

ADC, Andrew, Ericcson/Nokia, Alcatel-Lucent, Juni and LGC Wireless are the main ones I see.

Quick to install and easy to deploy in tough locations. Zoning and permitting is easy and sometimes not needed. Can be used over a number of mediums like copper or fiber optic depending on vendor.

Thanks TJ for your great answers

[RadioFoneGuy]

I didnt know the Media Converters would push it over Copper, I thought is was fiber only.

so do you put the BTS in at an existing tower a pipe it out?

[RadioRaiders]

DAS are usually used for indoor coverage of large office buildings, convention centers, in tunnels, subways, etc. It's usually one or 2 base stations in a central location, and then a bunch of small antennas (or a "leaky cable") connected to it and spread out. Can be copper, fiber or a mix of both.

Here's a good read:
http://www.ericsson.com/technology/w...Building_A.pdf

If you work for an operator, ask your equipment vendor for more info...

[TelcomJunkie]

Originally Posted by RadioFoneGuy

I didnt know the Media Converters would push it over Copper, I thought is was fiber only.

so do you put the BTS in at an existing tower a pipe it out?

Yeah there are a few older systems I've seen done over copper and I believe the indoor LGC wireless system can be done over CAT5.

[quote=RadioRaiders;509631]DAS are usually used for indoor coverage of large office buildings, convention centers, in tunnels, subways, etc. It's usually one or 2 base stations in a central location, and then a bunch of small antennas (or a "leaky cable") connected to it and spread out. Can be copper, fiber or a mix of both.
/QUOTE]

Good addition, places like convention centers, amusement parks, large hotels and businesses are all prime candidates for a indoor DAS system. Basically, anywhere where there is a large concentration of users and the carrier is unable to cover it well from external macro sites. DAS systems are not restricted by any means to just indoors, carriers utilize a lot of DAS equipment in canyons and dense residential areas.

Also, smaller carriers like Cricket and Metro are heavily utilizing DAS systems to quickly build out their network and then filling it in where it's needed with macro sites. Outdoor DAS systems can go from concept to activation in months compared to the typical multi-year process for macro cells.

[RadioFoneGuy]

Its really hilly were I am and alot of times sites cannot hand off in time or you just lose line of sights and drop calls in some of these areas.

I would like to see my company use some in my area.

[TelcomJunkie]

Originally Posted by RadioFoneGuy

Its really hilly were I am and alot of times sites cannot hand off in time or you just lose line of sights and drop calls in some of these areas.

I would like to see my company use some in my area.

I primarily work on DAS equipment, namely about 95% of my service area is composed of it and we're utilizing it in between valleys in the canyons and along mountain roads. Makes for a fun day at the office, quite often reminds me of when I worked CATV. Most of my equipment is on telephone poles!

[RadioRaiders]

Originally Posted by TelcomJunkie

I primarily work on DAS equipment, namely about 95% of my service area is composed of it and we're utilizing it in between valleys in the canyons and along mountain roads

Interesting, I've mainly only seen it used for indoor coverage (as mentioned: hotels, etc.) or in dense urban areas (extra capacity for busy streets, parades, etc.). Never seen it used in rural open areas. Altho, I guess it would be cheaper than building a bunch of sites for little capacity (..but what about repeaters?)

Anyway, for the DAS in rural areas, can you give an example, where the BTS is located, and how many antennas are connected, and how far away the antennas would be located (on average)?

[TelcomJunkie]

Originally Posted by RadioRaiders

Interesting, I've mainly only seen it used for indoor coverage (as mentioned: hotels, etc.) or in dense urban areas (extra capacity for busy streets, parades, etc.). Never seen it used in rural open areas. Altho, I guess it would be cheaper than building a bunch of sites for little capacity (..but what about repeaters?)

Anyway, for the DAS in rural areas, can you give an example, where the BTS is located, and how many antennas are connected, and how far away the antennas would be located (on average)?

The main problem with using a typical repeater is having a quality donor that can handle the capacity with clear line of sight. With the size of the system I maintain, it'd be impossible to do that. For the most part, DAS is just a direct connect repeater versus over the air. I'm using a mixture of different vendor fiber fed repeaters which in some cases are about 15 miles from the BTS.

[RedRyder]

Thanks all for the informative discussion. This covered well the areas for which I was looking for some info.

[spleck]

The Atlanta Airport has a system they like talking about:

Atlanta Airport DAS
Atlanta Business Chronicle article
LGC Wireless Case Study
MetroPCS Press Release

plus more if you Google it.

[kilovolt]

Interesting thread!

I've been watching Sprint install antennas this past spring along US 50 from Pollock Pines to Twin Bridges. It's been a notoriously bad stretch of road for cellular coverage because the road follows the American River canyon, and its very dense with trees. Not to mention very windy.

I started noticing antenna panels attached to telephone poles, and soon realized they were all connected. I've seen about 5 antennas so far, and I assume the are all connected together. And according to Sprint's coverage viewer, it is now active. I assume its all part of a DAS.

Now that I know what they look like, I've noticed them along Crow Canyon Rd between Castro Valley and San Ramon. That road gets a good amount of traffic, and I've often wondered how I'm able to have 5 bars of coverage nearly the whole way. (though I have to say the installation looks a bit shoddy - the antennas and cabling are rather messy looking and look like something I've seen in New Delhi).

[spleck]

Originally Posted by kilovolt

I've been watching Sprint install antennas this past spring...

Sounds like you need to take some pictures for us and post them in the gallery!