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I'm thinking about changing my home media setup so that I stream my video ISOs from a remote PC to my HTPC. However, I'm worried that 802.11g will be too slow to stream high quality video data, especially Blu-ray. Is 802.11g fast enough?
Craig
Posted 2012-07-24T04:24:41.067
Reputation: 135
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No, 802.11g will not be fast enough without compression of the video/audio stream. BD-ROM movies require a 54Mbps data transfer rate at minimum. It is true that 802.11g can handle data rates of 54Mbps, but there is also overhead when moving packets wirelessly. 802.11g will not be able to keep up with the required bandwidth of 54 Mbps for BluRay AND add overhead.
Everett
Posted 2012-07-24T04:24:41.067
Reputation: 5 425
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Blu-ray uses up to a 54mbps max (not min) data rate. 802.11g's top signaling rate is 54mbps, but it has overhead of over 50%. Around 23mbps is about the most you can see in ideal conditions (close to the AP, strong signal, no noise) with most equipment, and you could potentially see 30mbps with a client and AP that both do "frame bursting", and with a very efficient TCP performance testing tool such as IPerf. In the real world, if I'm getting TCP throughput over 15mbps on an 802.11g network, I consider it "good enough". Not bad for a technology that's over a decade old.
802.11n not only has much higher signaling rates, but it can acheive much lower overhead through the use of frame aggregation. 60% efficiency is common, and I've even seen as much as 77% efficiency under ideal conditions. That means getting 350mbps TCP throughput out of a connection that's using the top 450mbps signaling rate.
Wired Ethernet, in contrast, is about 94% efficient (when using TCP), so you can expect about 94mbps TCP throughput on an otherwise idle 100BASE-TX connection, and over 900mbps on an otherwise idle 1000BASE-T connection.
Spiff
Posted 2012-07-24T04:24:41.067
Reputation: 84 656
Would either 100Mbps (not Gigabit) or 802.11n be sufficient for BluRay? – Craig – 2012-07-24T04:36:21.837
1802.11n should work. My concern at that point is if the network from the source of the BluRay movie to the AP (access point) was Gigabit. 100 may work, but Gigabit guarantees it. I have NO WAY of knowing what other traffic would be on the network at any given time, so I can't guarantee that 100 Meg would handle the job. – Everett – 2012-07-24T04:40:14.870
FYI, according to Wikipedia, BluRays have a 4.5 MB/s read speed, which is about 36 Mbps. However, the Wikipedia article on 1080p states up to 40 mbps. Either way, I definitely concur with the need to account for overhead. – Craig – 2012-07-24T04:46:42.953
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That's the 1x format, or data format. The movie format with audio uses 54 Mbps. http://www.blu-ray.com/faq/
– Everett – 2012-07-24T04:49:52.410Glad to be of service. – Everett – 2012-07-24T04:56:50.420