[graham.myers]

I'm aware this needs a serious update I will try and write an update when I can

What are HomePlugs
HomePlug units enable you to expand your network using the existing electrical wiring within your home. The data travels from one HomePlug to another. No drivers are required, and they are operating system independent. Plug any Ethernet device into the HomePlug and away you go - High speed reliable networking. Truly Plug And Play!

For a more in-depth reading look on wikipedia - http://en.wikipedia.org/wiki/HomePlug

What is the difference between HomePlug and Powerline

Powerline is the technology, HomePlug is a standard for the Powerline technology.

There are two competing chipsets used in the technology. HomePlug uses Intellon based products, whilst other manufactures use a DS2 chipset and a are incompatible.

There is a HomePlug Powerline Alliance. The Alliance's mission is to enable and promote rapid availability, adoption and implementation of cost effective, interoperable and standards-based home powerline networks and products. http://www.HomePlug.org/home

How many HomePlugs do I need
You need at least one pair of HomePlugs. One unit will enter the ring main, and another is used to exit the ring main.

Would HomePlugs work on different mains circuits in my house (rings) ?
Yes, but the rings or circuits (such as upstairs and downstairs) mains must be on the same fuse box / consumer box.

In the US things are a little different. It’s common in the US to use Split Phase wiring where the building is split between two separate phases and HomePlug may not be able to cross phases.

How do I setup BT / Wanadoo / Demon / Tiscali / Virgin / and other ISPs with HomePlug technology ?
If you already have a suitable router just add one HomePlug at the router end and one for each PC. The standard USB modem provided free by many ISPs is not HomePlug compatible so you would normally replace this for a Router Modem. Note it is possible to use the USB modem in a Windows Internet share setup with HomePlug, but it is not the ideal configuration. Tiscali's MTU is 1500

How do I setup NTL / Telewest / Cable with HomePlug technology?
Same as above.

How do I setup AOL with HomePlug technology?
To use HomePlug with AOL you need to replace your AOL modem with an AOL compatible ADSL router. AOL uses a special way to communicate through a network so you need a certain model of router. Note the MTU value of AOL is 1400 not 1458 as with BT. Tiscali's MTU is 1500.

What do I need on my PC to make HomePlug work?
Your PC must be compatible with Internet access and have a LAN / Ethernet Port.

I have an Apple Mac, will HomePlug work properly?
Yes HomePlug works on most Apple Macs without using any software you just set the Mac to TCP/IP Internet.

How do I connect a router with a LAN Socket to my Computer - it only has USB’s?
Install a LAN card or select a suitable adaptor.

I already have a router with 2 or more ports will HomePlug work?
Yes connect one HomePlug to the Router and one HomePlug to each PC (or xbox etc) in the house.

Do I need to put a HomePlug into the router for each of my computers?
No only one HomePlug is needed at the router end.

How fast is 14Mbps and 85Mbps in Mega Byte per second?
approx 1.75 MBytes for 14Mbps and 10.6 MBytes for 85Mbps

Note ADSL and Cable connections are provided in Mbps, NOT Mega Bytes per second:
Here are some examples of ADSL to Bytes per seconds
Half Meg 512 connection = 64KBytes
One Meg 1024 connection = 128KBytes
Two Meg 2048 connection = 256KBytes
Four Meg 4096 connection = 512KBytes
Ten Meg 10240 connection = 1280KBytes
Twenty Meg 20480 cinnection = 2560KBytes

What is HomePlug AV?
This is the new 200mbs standard designed for use with Hi-def streaming.

Are all HomePlug versions compatible?
All 14mbs HomePlugs regardless of manufacture are compatible with each other as they all adhere to the HomePlug 1.0 standard. All 85mbs are interchangeable too as they adhere to the HomePlug 1.0 Turbo standard. HomePlug 1.0 and 1.0 Turbo are interchangeable so you can mix and match both 14 and 85mbs as well as manufacturers.

There are 2 makes of powerline chipsets. Intellon and DS2. The majority of manufactures use the Intellon chipset and adhere to the HomePlug standard and are interopable. However those that use the DS2 chipset cannot be used with Intellon based products. Phillips' HP products and Netgear's 200mbs units (HDX101) use the DS2 chipsets.

HomePlug AV (200mbs) can coexist but will not inter-operate with the HP 1.0 and 1.0 Turbo standards. This means you can have one set of HP 1.0 units and 1 set of AV units but they can't see each others kit. The manufacturers claim there is no drop in performance when mixing these but tests (on Tom's Hardware and SmallNetBuilder) indicate that performance can drop as much as 58%.

What is the actual speed I can attain with HomePlugs?
The ratings of 14, 85 or 200mbs are theoretical maximums. You will never achieve these speeds. This figure also includes the overhead of the data transmission protocol, for example the HomePlug AV (200mbs) standard has a maximum data rate of 150mbs. Additionally, the mains ring is a hostile place for data and pushing through the maelstrom of noise on the line slows down the packets. There are ways to speed up transmission as best you can, for example tighten the wires in all the outlets in you house (WARNING: Turn off the power first!). I have gone from 85mbs to 115mbs throughput by doing this one task (when using Netgear 200mbs plugs). It is not unreasonable to assume you will get approx 50% of the rated maximums. There are also various threads around the net that highlight issues with switched power devices such as phone chargers and hairdryers. Unplugging phone chargers can also increase performance.

If you are using Netgear's HDX101 200mbs units, the latest firmware implements a new feature called auto enable notches. Notches having something to do with reducing interference to hand-radio frequencies and this will lower the performance of the powerline network somewhat. Performance can drop as much as 25% becuase of this feature. Netgear's gui configuration program offers no option to disable notching, but you can with the commandline tools such as ihcp_client. See here for details - http://forum1.netgear.com/showthread.php?p=43905

When streaming content around the house using powerline technology then you are sending UDP packets of data. Most HomePlug products (definately Netgears HDX101) are optimised for sending UDP streamed traffic. If however you need to transmit lots of TCP traffic from a windows machine (mostly file copies etc) then you can amend the TCP window size to boost performance from the default 8K to 128K

Which HomePlug should I use?
This entirely depends on what data you want to distribute around the house. The 14mbs units should only be used for low transmissions equipment, for example you can purchase security cameras with HomePlug built in and these are 14mbs devices. Xboxes, PS3s etc should be using a minimum of 85mbs. If you wish to stream a lot of video or VoIP and/or Hi-Def you should be looking at 200mbs models.

How many HomePlugs can I use at home or in the Office?
HomePlugs are like old School Ethernet; they run on half-duplex. So only one device can send at a time. Technically 10 is probably the limit due to throughput in theory up to 254 could be used. Be aware that if you have BT Vision you may already have Comtrend's (DS2 based) 200mbs adapter in your package. Be carefull if buying additional powerline units - you may need to buy compatible DS2 based products.

Is software provided with HomePlug and how do I use it?
The software (usually only for Windows) allows transmission checks and adjustment of network names (encryption). Software drivers are not required for HomePlug the units are plug and play.

Do I lose the use of my power socket?
Yes, normally. Most HomePlugs are like normal power devices, they use up the socket you plug it into, some even are so large (Netgear for example) that they prevent larger items to be used in the socket next to them, for example transformers etc. You can get HomePlugs with a ‘through’ socket so you can still plug a device into them. A bit like the old cube style triple adapters you can get.

Is HomePlug secure?
Yes it is preset with its own 56bit encryption system to protect your data. HomePlug AV adopts a 128bit encryption system.

Don’t forget to check the security options on any wireless devices in the house. If an outsider can access the wireless network, they also gain access to the homeplug-connected computers, and the homeplug security is useless.

Can my neighbour steal my internet connection if he has a HomePlug?
No, the electricity meter acts as block on the signals that are transmitted across the network, so there is no chance of them leaking out on to the public wiring and your neighbours picking them up.

Don’t forget to check the security options on any wireless devices in the house. If an outsider can access the wireless network, they also gain access to the homeplug-connected computers, and the homeplug security is useless.

I don’t have a wired connection only wireless. Can I still use HomePlug?
Yes. Some manufacturers (such as Devolo) produce a wireless-g extender - http://www.devolo.com/co_EN_cs/produ...relessext.html

Can I use my Xbox on HomePlug?
Yes. The XBOX 360 has a 100mbs Ethernet port built in. Just plug it into the HomePlug

Fix: Xbox doesn't work with Windows Media Centre when connected by HomePlug.
Some makes of HomePlug work with IGMP V2 - windows extender uses IGMP V3. You need to modify the windows registry and set the Media Centre to IGMP V2.
Please see the following link on how to modify the registry.
http://support.microsoft.com/kb/815752/en-us

Can I use my Play Station 2 (PS2) with HomePlug?
Yes you will need a network adapter available from Sony, Amazon or another online retailer.

Can I use my Play Station 3 (PS3) with HomePlug?
Yes. The PS3 has a 1000mbs (gigabit) Ethernet port built in, just plug it into the HomePlug..

What stops HomePlug from working, will they work with extension Lead?
Avoid surge protected / Filtered mains extension blocks as these block the HomePlug signal. Long extension leads will degrade the signal so it is best practice to plug the HomePlug directly into a wall socket. I personally have one HomePlug in the wall socket and one plugged into a 4 gang and achieve 115mbs approx. There are also various threads around the net that highlight issues with switched power devices such as phone chargers and hairdryers. Unplugging phone chargers can also increase performance. Be aware that if you have BT Vision you may already have Comtrend's (DS2 based) 200mbs adapter in your package. Be carefull if buying additional powerline units - you may need to buy compatible DS2 based products.

How can I test the performance of my setup?
You need some kind of bandwith measuring tool. While most homeplug manufacturers distribute utilities that measure their products performance, in my experience they can be a little misleading. They measure the peak performance between the devices not a real world throughput test. Enter iPerf. You will need two PCs one on either side od the ring main. One runs as a client, the other as a server. Its deisgned as a TCP/UDP monitoring tool not just for homeplugs.

http://dast.nlanr.net/Projects/Iperf/

on the client you would….. iperf -c <server address>
on the server you would …. iperf -s

here’s an example….

node2> iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 60.0 KByte (default)
------------------------------------------------------------
[  4] local <IP Addr node2> port 5001 connected with <IP Addr node1> port 2357
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.1 sec   6.5 MBytes   5.2 Mbits/sec

node1> iperf -c node2
------------------------------------------------------------
Client connecting to node1, TCP port 5001
TCP window size: 59.9 KByte (default)
------------------------------------------------------------
[  3] local <IP Addr node1> port 2357 connected with <IP Addr node2> port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   6.5 MBytes   5.2 Mbits/sec

[huxley]

Very nice thanks for that.
One thing the PS3 has a gig lan port.

[graham.myers]

thanks. willl change that.

[SeanT]

If you want to stream hi-def at above 20Mbit/s my suggestion is to go out and buy a reel of cat 5 cable, this is from an engineer who has tested it using two 200 meg powerline adapters in the same MK double socket after they didn't work across the ring main at these sort of speeds - maximum throughput would appear to be limited somehow to around 2.6 MB/s - test conducted using the comtrend (BT) ones.

[mattrixdesign2]

Nice Q and A.

Can I just ask a few additinal Qs:

*Do these home plugs work fine with extensions, multiways etc - I presume so just checking.

*I have a Wireless DSL router on Virgin - my understanding from your FAQs is I can plug one of these home plugs direct into the the Wireless Router (via Ether Net), then plug the other home plug into my PC and get a wired connection.

Although I have no HD streaming requirements, I would like to stream Photos/Music/Movies - what is the minimum spec.

Who are the best manufacturers, in your opinion? Are these any good "Dynamode 85Mbps Homeplug Adapter - Twin Pack"?

Also have you heard of the Panasonic HD-PLC, as fas as I am aware they are NOT Homeplug compatible.

[graham.myers]

according to iPerf I get around the 115mb/s so around 14MB/s and dont have any issues streaming hi-def to my xbox. I'm using the Netgear 200mbs.

Seems strange your tests limit the speeds to only 2.6mb.

it could be the implementation. One thing I didnt mention in the faq is that on the Netgear units there is some kind of handshaking mode that if you turn off (with a hack) you can squeeze upto an extra 20% out of the units. Maybe the comtrend have similar manicles strapped to them.

Also changing the default TCP window size from the default 8k to 128k will yield a big performance boost too (or at least, again, on the hdx101s). I havent got around to doing this yet - its on my list but I wanted the rest of my network stable first but this is aimed at TCP traffic (file transfers) rather than UDP traffic which is what streaming predominantly is.

[edit] The hack relates to disabling notches - details here http://forum1.netgear.com/showthread.php?p=43905
Notches having something to do with reducing interference to hand-radio frequencies and this will lower the performance of the powerline network somewhat.

[graham.myers]

Originally Posted by mattrixdesign2

*Do these home plugs work fine with extensions, multiways etc - I presume so just checking.

answered in

Originally Posted by faq

What stops HomePlug from working?
Avoid surge protected / Filtered mains extension blocks as these block the HomePlug signal. Long extension leads will degrade the signal so it is best practice to plug the HomePlug directly into a wall socket. I personally have one HomePlug in the wall socket and one plugged into a 4 gang and achieve 115mbs approx.

Although I'll change the heading to

Originally Posted by faq

What stops HomePlug from working, do they work with extension leads?

Originally Posted by mattrixdesign2

*I have a Wireless DSL router on Virgin - my understanding from your FAQs is I can plug one of these home plugs direct into the the Wireless Router (via Ether Net), then plug the other home plug into my PC and get a wired connection.

correct

Originally Posted by mattrixdesign2

Although I have no HD streaming requirements, I would like to stream Photos/Music/Movies - what is the minimum spec.

answered here

Originally Posted by faq

Which HomePlug should I use?
This entirely depends on what data you want to distribute around the house. The 14mbs units should only be used for low transmissions equipment, for example you can purchase security cameras with HomePlug built in and these are 14mbs devices. Xboxes, PS3s etc should be using a minimum of 85mbs. If you wish to stream a lot of video or VoIP and/or Hi-Def you should be looking at 200mbs models.

Originally Posted by mattrixdesign2

Who are the best manufacturers, in your opinion? Are these any good "Dynamode 85Mbps Homeplug Adapter - Twin Pack"?

cant really comment on that. I was trying to be impartial I dont recommended the ones I use (Netgear HDX101) cos they're a lot more expensive than the others and they are not HomePug AV compliant.

Originally Posted by mattrixdesign2

Also have you heard of the Panasonic HD-PLC, as fas as I am aware they are NOT Homeplug compatible.

mention here

Originally Posted by faq

Are all HomePlug versions compatible?
All 14mbs HomePlugs regardless of manufacture are compatible with each other as they all adhere to the HomePlug 1.0 standard. All 85mbs are interchangeable too as they adhere to the HomePlug 1.0 Turbo standard. HomePlug 1.0 and 1.0 Turbo are interchangeable so you can mix and match both 14 and 85mbs as well as manufacturers.

There are some manufacturers (such as Phillps and DS2) that have powerline products but do not stick to the HomePlug standard and
thus are incompatible with any other manufacturer.

200Mbs however the waters get a little muddy. Most manufacturers stick to the new standard called HomePlug AV. All manufacturers who use this standard are interchangeable. This excludes Netgear; they went it alone with their own standard. Any 200mbs HomePlug AV may connect to 14 or 85mbs equipment. The standard states they must co-exist with the HomePlug 1.0 but interaction is optional. You can however have them plugged into a router or switch which will act as a bridge between the two networks. So you could have a server on a 200mbs HomePlug in one room, plugged into a 200mbs HomePlug which plugs into a switch. A second port on this switch then plugs into a 14mbs or 85mbs home plug which subsequently connects to another similar device. You of course need two pairs of HomePlugs (a pair of 85S and a pair of 200s) for this scenario

[mattrixdesign2]

I didn't read your FAQs too well then

Good work though!!!

Thanks

[graham.myers]

no worries, I'm sure it will evolve and be made clearer as more input is posted.

I'm looking at the performance side of things now so will add sections on the relevent manufacturers if I can find the info.

[graham.myers]

Originally Posted by SeanT

If you want to stream hi-def at above 20Mbit/s my suggestion is to go out and buy a reel of cat 5 cable, this is from an engineer who has tested it using two 200 meg powerline adapters in the same MK double socket after they didn't work across the ring main at these sort of speeds - maximum throughput would appear to be limited somehow to around 2.6 MB/s - test conducted using the comtrend (BT) ones.

It looks like the Comtrend devices also use the DS2 chipsets. Perhaps they have the notches option turned on and that is why you are seeing low bandwith.

[Kazza72]

Great post, thanks.

Can I just clarify - I have a wireless set-up: talktalk ISP, netgear wireless router which is hardwired to my xbox 360 and connects wirelessly to laptop and imac. Can I buy two homeplugs and simply plug one in and connect it to the netgear router via ethernet and plug the other one in where my wireless signal is weakest.
Ie, does one homeplug HAVE to be wired to a PC, or is the router sufficent.

Thanks.

[graham.myers]

any device that can run across a wired ethernet can run across homeplugs

[graham.myers]

ok, been a experimenting with my network. I've been having a bit of fun over the last week with the security cameras timing out etc and on the back of Sean's comments I'd thought I'd do some tests.

I have HDX101's from Netgear rated at 200 mbs. Previously I was getting really low connections (<15mbs) and so tightened up all my connections and got very good performance (>100mbs). I also did the hack to turn off notches in the latet hdx101 firmware.

today however, I've been running iperf. My desktop is the client running windows XP SP2 (with a TCP RWIN of 128k) and the server is a linux (fedora 8) with a TCP Receive window packet size of 256k

iperf with a TCP packet size of 8k (the windows default) gives me a throughput of 19.1 mbs - very close to what Sean says.

I currently have adjusted this value to be 128k. You all have adjusted your TCP receive windows size haven't you?

iperf for this value gives me 54mbs

if I try to increase the packet size, to say 256k, I get 69.7 mbs

Trying 512k yields a bandwith of 55.9 mbs - starting to bite and impact on the bandwith. So for me a 256k (from my current 128k and Windows 8k) will give the best results on my current network topology

no way what I used to get - I guess there is something on the network (the mains network) that is interfering - I suspect some power supply

I'll start a section on known bandwidth leaches as and when people find them (hopefully starting with me )

[mattrixdesign2]

Originally Posted by graham.myers

ok, been a experimenting with my network. I've been having a bit of fun over the last week with the security cameras timing out etc and on the back of Sean's comments I'd thought I'd do some tests.

I have HDX101's from Netgear rated at 200 mbs. Previously I was getting really low connections (<15mbs) and so tightened up all my connections and got very good performance (>100mbs). I also did the hack to turn off notches in the latet hdx101 firmware.

today however, I've been running iperf. My desktop is the client running windows XP SP2 (with a TCP RWIN of 128k) and the server is a linux (fedora 8) with a TCP Receive window packet size of 256k

iperf with a TCP packet size of 8k (the windows default) gives me a throughput of 19.1 mbs - very close to what Sean says.

I currently have adjusted this value to be 128k. You all have adjusted your TCP receive windows size haven't you?

iperf for this value gives me 54mbs

if I try to increase the packet size, to say 256k, I get 69.7 mbs

Trying 512k yields a bandwith of 55.9 mbs - starting to bite and impact on the bandwith. So for me a 256k (from my current 128k and Windows 8k) will give the best results on my current network topology

no way what I used to get - I guess there is something on the network (the mains network) that is interfering - I suspect some power supply

I'll start a section on known bandwidth leaches as and when people find them (hopefully starting with me )

I know you seem to have invested time and money already, but from what a gather from a recent presentation in work - the Panasonic range of Network Cameras & their "homeplugs" all work together nicely.

[graham.myers]

sticking with the same make througout will ensure a high level of compatability. With Phillips using DS2 chips rather than Intellon they're not HomePlug compatible. But sticking with Philips throughout would ensure they all hang together.

I did have homeplug cameras (from solwise, so they'd be Intellon HomePlug 1.0). they were rubbish but I did get them working with the DS2 based Netgear 200mbs. I used a Netgear HDX104 85mbs unit which is Intellon based homeplug plugged into the same router as the HDX101 to act as a bridge between the two disparate technologies.

The HomePlug cameras went back and I got wifi ones instead - they wouldn't work with the linux based security system software I was using.

[andi1]

im wanting to use home plugs to stream music from pc upstairs to downstairs hifi, do i need a router or can i just plug the computer ethernet into the home plug upstairs and then the squezebox ethernet cable into the homeplug downstairs?

im not using it for internet or anything like that.

thankyou

[cwick]

Yes, that would work just fine. You would need to setup fixed IP addresses for each device though (PC & Squeezebox), since a router would normally provide them with IP addresses when they connected to the LAN.

[andi1]

Originally Posted by cwick

Yes, that would work just fine. You would need to setup fixed IP addresses for each device though (PC & Squeezebox), since a router would normally provide them with IP addresses when they connected to the LAN.

Ahh i see thanks have you any idea how to do that in windows xp is it in control panel?

[mattrixdesign2]

I have recently bought 2 home plugs and they worked great. This was my setup:

Virgin modem ==> Wireless router ==> wired connection ==> HomePlug

I had my PC connected to the other home plug for a wired connection, and my PS3 connected to the router via wireless.

Although eveything works I would like to have my PS3 wired, I could just add another plug, but I have also thought about moving the wirless router else where (closer) to where my Mrs uses his work laptop.

Can you confirm if the following will work...

Virgin modem ==> HomePlug ==> PC (via HomePlug) / PS3 (Via HomePlug) / Wireless Router in another location (connected Via HomePlug)

So basically I need to know of I can use the home plugs to "re-locate" my router away from the BB modem.

[graham.myers]

No, the modem will need plugging into the router and the other devices via the router wether they're plugged via homeplugs or wireless.

its the routers job to take the WAN and convert it to a LAN. Homeplugs run on the LAN. The router will convert your external IP address to an internal 10.x or 192.x IP address for your devices in the house.

if, because of bad wireless signals you needed the router nearer the laptap, it might be cheaper to get a cheap and chearful wireless AP, rather than more homeplugs

[mattrixdesign2]

OK, thanks for that info.

Well I can either buy another home plug or get another wirless router with more LAN ports (so I can plug in the PS3 direct as its next to the router).

[greycounciller]

OOops !
Just seen this on the Netgear site........http://www.netgear.co.uk/xe103_recall.php

[trickstar]

can someone please tell me if this set will work. or do i need separate homeplugs for each device.

Internet (cable) ==> Router ==> HomePlug -\/\/\/\/- HomePlug ==> 8 Port Switch/Hub ==> (htpc / ps3/ xbox /...)

-\/\/\/- = power line


regards
tricks

[graystreet]

Yep that'll work fine. Much the same setup as I've got for the kids' PS3 and Xbox apart from I'm on ADSL BB rather than cable.

[trickstar]

^^ thanks.

i thought you had to use an adapter for each device.

[graystreet]

No a switch will work fine, and it's somewhat cheaper than several homeplug adaptors

I would like to use Homeplugs but cannot find any information about their actual size. The space between my wall sockets and the floors varies from 1.5 inches to 2.5 inches. The comments in this thread suggest that for best results the Homeplug should be put directly into a wall socket and not into an extension lead.
Illustrations on the web seem to suggest that plugs project quite a long way down. They don't show how much space is needed between socket and floor or where the wires to the router and computer project out I just want to be able to use my only computer (a laptop) quickly and simply in other rooms in the house.
I deduce that I will need a new router as I only have the simple Speedtouch device that was supplied with my broadband service. I would also like to be as economical as possible.
Any advice would be much appreciated.

[SeanT]

What speedtouch is it? If it's USB only then you deduce correctly.

[DavieW]

Bought a pair of Advent 200MBit homeplugs for £99.99 from PC World yesterday, along with a Netgear Gigabit network switch for £24.99.
I'm using these to link my Pioneer VSXLX70 receiver and BDPLX70A blu ray, to my PC upstairs.
Dead easy to set up and get going and it performs really well streaming my media files.

Homeplugs deffo get a thumbs-up from me

Dave

[jaydee999]

Originally Posted by graham.myers

[SIZE="4"][COLOR="SeaGreen"]
Would HomePlugs work on different mains circuits in my house (rings) ?
Yes, but the rings or circuits (such as upstairs and downstairs) mains must be on the same fuse box / consumer box.

Hi Graham. I have two fuse boxes running off the same Electircity Board Box (for want of better words). Is this what you mean by consumer box? I want to use these plugs in a situation where one room (with the router) runs on one of the rings from one fuse box, and the other rooms (each with a PC in, but which both really struggle to maintain a wireless connection) run on a mains ring from the second fuse box. But they do both take their power from the same source. Is this OK, or am I stuffed?

Cheers

jaydee