Powerline Speed Based On Slowest Node?

[bmn1]

Hi,

Shortversion: Using the Netgear Gigabit Ethernet adapters around my house along with the Powerline 1000 wifi adapter. If I add another wifi adtaper but choose the 500 version will this slow my whole network down or only the computers connected through the 500 wifi node? What if I also add a desktop to the network through the 500 Ethernet wall plug?

Thank you for looking into this!

Long version: I updated my the powerlines in my house. In my house I currently have a Netgear PL1200-100PAS Powerline 1200 Gigabit Ethernet Adapter plugged into the router and then the same adapters plugged into the wall at their respective desktop computers. At another part of my house I have the NETGEAR PowerLINE Wi-Fi 1000 - Essentials Edition (PLW1010-100NAS) installed. If I decide to add a NETGEAR Powerline 500WIFI 802.11n Wireless Access Point (XWNB520) at another location will that slow my entire network down to the highest speeds of the Powerline500 or will it only slow down the computers connected to that particular Powerline 500 wireless node?



Thank you for looking into this!

 

[thiggins]

Hi,

Shortversion: Using the Netgear Gigabit Ethernet adapters around my house along with the Powerline 1000 wifi adapter. If I add another wifi adtaper but choose the 500 version will this slow my whole network down or only the computers connected through the 500 wifi node? What if I also add a desktop to the network through the 500 Ethernet wall plug?

Thank you for looking into this!

Long version: I updated my the powerlines in my house. In my house I currently have a Netgear PL1200-100PAS Powerline 1200 Gigabit Ethernet Adapter plugged into the router and then the same adapters plugged into the wall at their respective desktop computers. At another part of my house I have the NETGEAR PowerLINE Wi-Fi 1000 - Essentials Edition (PLW1010-100NAS) installed. If I decide to add a NETGEAR Powerline 500WIFI 802.11n Wireless Access Point (XWNB520) at another location will that slow my entire network down to the highest speeds of the Powerline500 or will it only slow down the computers connected to that particular Powerline 500 wireless node?

All HomePlug adapters share the same frequency spectrum and are on the same network. You can control which adapters "see" each other by changing the encryption key. This will prevent them from sharing data, but they still share the same bandwidth.

So yes, when the HomePlug 500 adapters ARE ACTIVE, they will slow down the HomePlug 1000 (AV2) adapters.

 

[steve23094]

All HomePlug adapters share the same frequency spectrum and are on the same network. You can control which adapters "see" each other by changing the encryption key. This will prevent them from sharing data, but they still share the same bandwidth.

So yes, when the HomePlug 500 adapters ARE ACTIVE, they will slow down the HomePlug 1000 (AV2) adapters.

What's the definition of 'active' please? I imagine streaming a movie would mean a constant active connection. But what about browsing the web, whilst you're reading the page is it considered inactive? Do fast HomePlugs quickly ramp up speed once a slower connection becomes inactive?

 

[thiggins]

Active means transmitting data.

 

[steve23094]

Active means transmitting data.

Dear anybody that can help and has experience in this matter,

I'm revisiting this because it's all about as clear as mud to me, and I'm wanting to pull the trigger on a purchase.

My scenario is I have my main router in one room that connects to a 1000Mb rated Powerline adapter. In my first bedroom I have a second 1000Mb PL adapter, and hanging off that an Apple Airport Express in bridge mode (my main router supplying all static IP addresses etc).

I have an older 500Mb Powerline adapter I want to install into a second bedroom and then connect a second wireless bridge off that one.

Would the second wireless bridge device be constantly communicating back to the main router to get DHCP info etc? Does that count as transmitting data and so will my PL network always be communicating at the slower 500Mb speed?

Thank you.

 

[thiggins]

Any network activity makes a node active. The wireless bridge itself would not be likely to be generating continuous data.

Throughput is reduced only during the time the slower network is actually transmitting data.

 

[sfx2000]

Legacy support (assuming one is HPAV2) is going to be at the level of the receiving node...

In a homogenous HPAV2 - each node has it's bandwidth in a multi-node environment - so if one has two "good" and one "not so good", that one node will be slow, but it shouldn't impact traffic between the two "good" nodes...

The HPAV2 PHY spec suggests as much... each node defines it's capabilities and PHY rate, and the scheduling there comes into play...

 

[News at 11]

A network is always reduced for to the lowest bandwidth of an active node, this applies to Wi-Fi, ethernet, MoCA, and HomePlug. For a can't miss explanation, watch section two of this video.

 

[sfx2000]

All HomePlug adapters share the same frequency spectrum and are on the same network. You can control which adapters "see" each other by changing the encryption key. This will prevent them from sharing data, but they still share the same bandwidth.

So yes, when the HomePlug 500 adapters ARE ACTIVE, they will slow down the HomePlug 1000 (AV2) adapters.

Actually they don't... took me a while to dig into the specs, but interop between AV500/AV2 is just fine, according to specs.

That being said - if a node is AV500, let's say, and another node is AV2-1200, the link will be based on AV500, as AV2 is backwards compatible, and must support older versions of the HPAV spec...

So if node (a) is AV500, node (b) is AV2-1200, and node (c) is AV2-1200 - data between node (a) and node (b) is AV500, data between node (b) and node (c) is AV2-1200, and data between node (c) and node (a) is going to be at AV500... taking into consideration distance and Signal/Noise ratios...

Each node knows it's bandwidth, and transmission from peer node to peer node is at a given speed - and nobody can transmit out of turn...

Putting in in lay terms - think of being at a conference table in a meeting, and rules are only the person with the "speaking stick" can speak at any given time, and they have a buzzer limit on how long they can speak - that's a scheduled MAC layer, which is what HPAV is - it's Time Division Duplex Multiple Access...

And this essentially supports @thiggins statement above, and I'll quote...

Throughput is reduced only during the time the slower network is actually transmitting data.

So yes, one can run a mix of AV500 and AV2-1200, and it should work fine - even to a point of mixing vendors...

I wouldn't recommend it, but there's nothing that says it cannot be done...

 

[System Error Message]

the most important thing about mixing adapters is that they're all MU-MIMO as that helps too.
So assuming 2 adapters of the same standard that support MU-MIMO, the bandwidth between 2 nodes isnt necessarily slowed always. For example given 4 rooms, all of them seperated by fuses, if there are 3 AV2000 and 1 AV500, when the av500 is talking with another av2000 it only slows down communication between the other 2 av2000 a little, not to the limits of the av500. This is because the av2000 uses additional channels/frequencies to communicate too and it is also further away.

When communicating between the av500 and av2000, the speed is limited to the av500. However if 1 av2000 is communicating to another av2000 and the av500 at the same time, its possible for the av500 to talk at its full speed and the av2000 will still have bandwidth to spare for the other av2000. So mixing is fine and just be sure to use the latest standards of powerline as they have more mechanisms for multiple adapters talking together.

It would be nice if someone could test this though.

 

[thiggins]

the most important thing about mixing adapters is that they're all MU-MIMO as that helps too.

HomePlug does not support MU-MIMO.

There are AV2 SISO and AV2 MIMO adapters. No AV2 MU-MIMO.

 

[System Error Message]

HomePlug does not support MU-MIMO.

There are AV2 SISO and AV2 MIMO adapters. No AV2 MU-MIMO.

yeah thats what i meant, MIMO adapters.

 

[sfx2000]

However if 1 av2000 is communicating to another av2000 and the av500 at the same time, its possible for the av500 to talk at its full speed and the av2000 will still have bandwidth to spare for the other av2000. So mixing is fine and just be sure to use the latest standards of powerline as they have more mechanisms for multiple adapters talking together.

In HomePlug, it's a scheduled MAC - so your use case is invalid - AV2000 will talk AV500 to an AV500 adapter, but it will talk AV2000 to an AV2000 adapter - they all take turns, so you'll never see AV2000 talking to AV500 and AV2000 nodes at the same time concurrently...

 

[System Error Message]

In HomePlug, it's a scheduled MAC - so your use case is invalid - AV2000 will talk AV500 to an AV500 adapter, but it will talk AV2000 to an AV2000 adapter - they all take turns, so you'll never see AV2000 talking to AV500 and AV2000 nodes at the same time concurrently...

they do take turns but in the case of the av500 and av2000, it doesnt use all the frequencies or channels that the av2000 uses so its possible for them to communicate concurrently.

Still this needs to be tested.

 

[sfx2000]

they do take turns but in the case of the av500 and av2000, it doesnt use all the frequencies or channels that the av2000 uses so its possible for them to communicate concurrently.

Doesn't matter... they all sync on the same freq's - so every node knows the timing based on the master node (central coordinator, aka CCo) - and they can only transmit in turn...

Nice technical article here -- http://www.homeplug.org/media/filer...aa82-179e6e95cab5/hpav-white-paper_050818.pdf

 

[sfx2000]

Anyways - like I mentioned before - it should work - there is a loophole in the spec, and this is where chipsets might come into consideration...

The AV PHY enables coexistence and interoperability with HomePlug 1.0 devices. The specification requires coexistence but interoperability is optional. Coexistence means that AV devices are capable of the low-level communications with 1.0 devices needed to share the medium, but not necessarily the ability to communicate payload data. An optionally interoperable device has the ability to communicate payload data with 1.0 devices. ​

Optional and should are scary words for standards guys, and generally a result of some compromise there...

On a single chipset vendors - e.g. all nodes are Broadcom or QC-Atheros, it should be fine... and most Vendors/OEM's would like it that way...