[Infotainer]

I am looking at building a small media service server for buses with upto 72 clients connected to it for HD content. Can any one suggest me a suitable piece of hardware , preferably low power, light weight and compact (possibly fanless) that can service a load of 72 clients.

Since I am using wifi 802.11n , I would need to downsize the videos as well before streaming.

Any help will be most welcome.

Infotainer.

[DJ_Izumi]

Without multicasting, which would remove the option for interactive interaction with media, I can't imagine ANY wifi network, not even 802.11ac, having enough bandwidth to steam HD media to 72 clients simultaneously in such a small enclosed space... o.O;;;;

Even sharing a Gigabit ETHERNET connection, you'd only have an average of 13.8 mbps available for each of the 72 clients.

It's a bus, I say just let everyone watch Netflix on their smart phone/tablet and their own data plan. o.O

[aesalazar]

Does it need to be HD? If it is a bus with small screens on the back of seats the difference between sd and hd is minimal. Even still, doesnt sound possible with WiFi.

You can look into what the airlines use for their interactive systems. Last time I flew Emirates they had a pretty amazing system that allowed what you are looking for. Not saying you could consider a system of that level - I am sure it is super expensive. But its a start.

I remember seeing an online video where they had 4 ethernet cards in a pc/server and was able to output 4 x full gigabit steams at the same time. Something like that might be what you need (sorry, cant find the link).

Ernie

[nickr]

I can't get the connect between "HD" and "downsize the videos" - not really much point in having HD then downsizing it to fit 72 streams into whatever bitrate you will squeeze out of 802.11n.

I mean look at the crap picture quality you get on an aeroplane with wired connections!

[touser]

The only way you're going to be able to have the available wireless bandwidth to service 72 simultaneous clients at any reasonable video bitrate is to use many extremely low power access points to distribute the wifi load. Have you put much thought into that? Honestly the hardware to store the content on and serve it is pretty straight forward compared to your wireless problem. There are many industrial fanless options available like this: http://www.anandtech.com/show/6908/compu...ivy-bridge

[Infotainer]

Only a Connoisseur will know the difference. For retrofit solution, where laying a wired network is not feasible , wireless is the only solution.

Choice is between not having an infotainment system and having one. The idea is to harness the low cost tablets and make them work as infotainment points. And tablets do not have Ethernet!

I appreciate picture quality will suffer but there is scant we can do!

Infotainer.

Without multicasting, which would remove the option for interactive interaction with media, I can't imagine ANY wifi network, not even 802.11ac, having enough bandwidth to steam HD media to 72 clients simultaneously in such a small enclosed space... o.O;;;;

Even sharing a Gigabit ETHERNET connection, you'd only have an average of 13.8 mbps available for each of the 72 clients.

It's a bus, I say just let everyone watch Netflix on their smart phone/tablet and their own data plan. o.O

I can't get the connect between "HD" and "downsize the videos" - not really much point in having HD then downsizing it to fit 72 streams into whatever bitrate you will squeeze out of 802.11n.

I mean look at the crap picture quality you get on an aeroplane with wired connections!

[Infotainer]

Thanks Touser,
I think the machine is good. I would prefer buying a model that is locally available : Can you help me by suggesting: what is the minimum specification i should be looking at? Would any standard Industrial PC with core i3 do? What kind of RAM should i be looking at? I feel a wired 1Gig Ethernet connection is a must- how else would you pipe the data to the wireless router?
What should be the add-on for enhancing performance? I feel a SSD or a 7200rpm HDD would be any day better. Since it is a automotive application- an SSD would be better. Comments?

Then I may want to add an encoder for 1 or 2 Satellite TV channels. The server should be able to handle the encloding load also.


A noob question- do you think an I7 with a 5400rpm drive will be able to serve 72 simultaneous accesses to media and handle encoding?

The only way you're going to be able to have the available wireless bandwidth to service 72 simultaneous clients at any reasonable video bitrate is to use many extremely low power access points to distribute the wifi load. Have you put much thought into that? Honestly the hardware to store the content on and serve it is pretty straight forward compared to your wireless problem. There are many industrial fanless options available like this: http://www.anandtech.com/show/6908/compu...ivy-bridge

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Touser,
One thought that I have had is to add a Ethernet switch and add 2-3 Wi-Fi spots in a coach. But I feel that would not really help increase throughput, as the radio channels of the routers would be competing with each other.

Any thoughts on that? can you suggest any low power access points that I could use?
I appreciate putting a low power router to service the loads by placing one at the rear and one in the front may help.

[DJ_Izumi]

Yeah... The hard drive is gonna be another issue. With my example of 1gbit Ethernet, the problem is, no single off the shelf HDD can even saturate a 1gbit Ethernet connection, not by a long shot. That's also only when doing a SINGLE sequential read off the drive even. Trying to feed possibly 72 files simultaneously that would be located in different geographical locations off the hard drive? That in itself would present a major hurdle to cross.

[nickr]

Well you could put all the wifi hotspots on different channels and the interference could be minimised.

Why are you stuck on tablets? Wired ethernet will give much better results.

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What about something like this? http://www.alibaba.com/product-gs/711245...creen.html

[Infotainer]

@ nickr
1. its retrofit solution wiring is to be kept minimum.
2. Cost of hardware- Tablets are lowest cost. From China - start at USD40 for a 7" screen. If I add Ethernet, I will need to do a tablet+USB to ehternet converter. Pushing up cost.

Idea is low cost infotainment.

[Dam0]

um, the unit you mention above is by no means HD capable...

Display resolution: 800x480

im not sure if mali 400 will hardware decode for xbmc yet, i know its not for nix anyway. if its not, then 1.2Ghz single core cpu prolly isnt enough horses under the hood for decent frame rate.

D.

[CaptainPsycho]

In my oppinion you will need a good and fast SSDs instead of HDDs. 72 Streams parallel will be close to random reads.

When you are also going to transcode 72 Streams parallel you'll need to a monster of CPU.
So just save suitable versions of your media on ssd and don't transcode on the fly.

[Infotainer]

thanks Captain.. I had zeroed on SSD. I am planning to avoid transcoding. Keeping only transcoded media.

[Infotainer]

Hi! The client for whom I started working has woken up again. I am now using super lost cost tablets and would not be playing videos of resolution better than 480P, I think this will require about 1.2Mbps per screen, giving me a total throughput requirement of about 84mpbs which looks achievable using an 802.11n network- Yes/No?
Using a QNAP server with sufficient R/W capability./

Now I am stuck on the DLNA server software and the app I can use on the tablets to make this happen. Any suggestions??
Is XBMC a plug in for my needs?