Tag: WiFi wireless

802.11r – the new wireless-networking standard

In August-September 2008, there has been a fair bit of talk in the IT press about the new IEEE 802.11r standard for wireless networks. It isn’t a new waveband or transmission standard for these networks.

Instead it is an improved method of handling the “handover” procedure when a wireless-network client moves between two access points in a multi-access-point network. The idea behind this is to make the handover process hard to notice if you are using a multimedia service which works with streamed audio or video like VoIP or audio / video streaming. The same feature will also benefit multi-machine multi-player gaming such as Internet-hosted online gaming because everything that is part of the game is kept in sync, thus making sure that you can “frag” the opponent there and then. With current technology, if you move between different access points while using a multimedia service, you will notice an obvious “glitch” because of the requirement to re-associate with the network when in the new access point’s area.

The improvement is based on a “work-ahead” procedure where the client will log in with access points of the same “extended service set” while utilising the current access point. Then it will “switch over” to whichever access point has the best signal, thus avoiding unnecessary glitches.

The main issue with this technology, like any new standard being introduced, is how it can work with existing networks and equipment. As well, there is the issue of an upgrade path for existing equipment. In the first situation, would 802.11r-based clients be able to achieve the fast handover with wireless networks that work with current technology and would 802.11r-based access points work with existing WiFi clients. This also includes wireless networks where some access points may be 802.11r-enabled and some may be on existing technology. This would typify operating environments where a gradual roll-out is implemented because there will be an initial price premium for newer equipment being equipped with 802.11r and it would still wouldn’t be cost-effective to replace all access points at the same time. This brings me to what will be discussed in the next paragraph regarding existing equipment.

The second situation would determine what is needed to be done to an existing network to roll out the new technology. Could this be achieved through a firmware or software upgrade on existing equipment or would it require totally-new equipment to be deployed? This issue would be very pertinent when it comes to small wireless networks where one of the access points is built in to a wireless router that is on the network-Internet edge. It also would encompass most outdoor access points and, of course, those HomePlug-based wireless access points like the Netcomm NP-290W / Solwise PL-85PEW which I have mentioned about in this blog.

This issue may not be exposed in the small-network space because the typical small wireless network is based around only one access point — the one built in to the router at the network’s “edge”. But as I have mentioned in this blog about setting up multi-access-point wireless networks which have an Ethernet or HomePlug wired backbone as a way of extending the wireless network or conquering wireless-network reception difficulties, the issue of the 802.11r “fast-handover” technology will have to be exposed to this class of network. This is important if the network is being used for VoIP, streamed IP-based multimedia or online-gaming “frag-fests”.

Feature Article: Extending your wireless network's coverage

 Many of you who have viewed this blog have been looking for information about extending the wireless segment of your home network. Typically it may be to cover a large house or to gain wireless coverage past a radio obstacle like thick brick / stone walls, foil-lined insulation or double-glazing which uses metal-based heat reflection techniques. Previously, I have mentioned about using this technique to mitigate microwave-oven interference on the 2.4GHz band which 802.11g works on.

 

Most wireless-network equipment manufacturers have released repeater devices that catch the existing wireless-network signal and expose it in to the new area. Some of these setups work on a vendor-specific manner or may work according to standard WDS bridging techniques. But they all require the use of equipment compatible with each other, usually equipment supplied by the same vendor.

The “extended service set”

The method that I am going to talk about here is the establishment of an “extended service set” comprising of multiple access points serving the same network and using the same SSID and security parameters. All the access points have to be connected to a common wired-network backbone which is part of the same logical network; and the access points must be working on the same technology – the same 802.11 variation and operating mode (G-only, N-only, mixed mode, etc)

This method can be performed with access points or wireless routers supplied by different vendors, thus permitting the use of equipment which is suited for the job at hand. It can allow for use of surplus routers simply as access points as long as they are configured correctly.

The diagram below shows what a small network should be like when running an extended service set.

Home Network with extended wireless segment

The network backbone

The wired-network backbone can work on any wired-network media such as a Cat5 Ethernet, HomePlug power-line, fibre-optic LAN, MoCA TV-aerial coax, HomePNA phone-line or a mix of these technologies bridged to each other. It can even work with a dedicated inter-building wireless backbone that may be used for larger properties or to join shops separated by a street.

The network backbone can handle other network traffic from wired-network devices like servers, desktop computers and games consoles; and become the network’s local data path to the Internet. This is while it works as the backbone for the wireless “extended service set”.

You may have be lucky to have an Ethernet cable in your house if you had it “wired for data”. But most houses typically wouldn’t have this facility everywhere.  The other technology that I have found to do this job equally well is HomePlug powerline networking which works over the cable infrastructure used to provide AC power to your lights and appliances. It can reach further than the existing building, which is a boon if you need to extend coverage to garages, sheds, cabins or other outbuildings or have Internet access in a caravan or campervan used as a “sleepout” or mobile office.

Access Points

These devices are the transmitters that bring the data from the wired network backbone to the wireless client devices and make up the extended service set.

You typically will have one such device in the form of your wireless router which is at your network’s Internet-network “edge”. The wired-network backbone used as part of this “extended service set” would be connected to one of the LAN ports on this device. If you use a wireless router with one Ethernet port for the LAN and that port is used for a desktop computer or similar wired-network device, you will need to expand the number of sockets by using an Ethernet switch. These will typically be a “dime a dozen” for a five-port or eight-port unit. There are also some HomePlug-Ethernet bridges that have a built-in four-port switch that are worth considering if you are setting up a HomePlug backbone.

Repurposing the old wireless router

If you upgraded your wireless router to a newer model, you will still have your existing router gathering dust. This can work as an access point but will need to be configured appropriately. You will need to disable the following functions:

* DHCP server

* UPnP Internet Gateway Device functionality (typically referred to as UPnP)

* Dynamic DNS functionality (if used)

As well, you will need to set the LAN IP address to something that is within your network’s IP address range but preferably out of the address pool used by the current router. The reason you have to take care of this setup is because there needs to be only one device performing “network-Internet edge” functions such as DHCP in a network and this device should be the one at the logical network-Internet border.

When you connect this router to the wired backbone, you use any of the LAN ports to connect the backbone. Never use the WAN port on this router for the wired backbone.

“3-in-1” HomePlug wireless access points

There is an increasing number of wireless access points that work with a HomePlug or Ethernet backbone. These devices, such as the Netcomm NP290W / Solwise PL-85PEW and the Devolo dLAN Wireless Extender, are as big as a compact “wall-wart” power adaptor used to power most electronic devices from the mains and plug directly in to the power outlet. They bridge between an 802.11g wireless segment (as an access point or wireless client bridge), a HomePlug powerline segment and a Cat5 Ethernet segment.

These units come in handy if you need to extend a wireless network on a temporary basis or simply if a compact device can do the job better than a large access point. They would come in to their own when you are using the extension access point to mitigate microwave-oven interference in the kitchen or if you want to extend the home network to a static caravan.

Configuring the access points

You will need to know the SSID and the WEP or WPA wireless security parameters that are operational for your network. These are the only factors that need to be common amongst all of the access points of the network. The reason that the SSID and security parameters are set to the same details is so that wireless client devices can roam between the different access points without any user intervention.

The radio channels for each of the access points have to be set differently to each other. It is a good idea to set the access point closest to the kitchen to Channel 1 if you have a microwave oven in that kitchen. This is because, from my research, most of the domestic-market microwave ovens work at 2450 MHz which is between Channels 8 and 9 on the 802.11g channel list. I had tried an experiment to see whether a microwave can upset a wireless-network “cell” that is tuned away from its operating frequency.

The wireless client devices

There is no need to reconfigure any of the wireless client devices such as laptop computers once you have set up the network according to the above instructions.

You will see an improvement in network performance when you operate your wireless client devices in areas where you barely could operate them. The signal-strength bar-graph that is part of your wireless client device’s network management software will register a stronger signal as the client device comes in to vicinity of the access points.

Conclusion

Once you have followed the steps in this article, you will be able to extend the effective coverage of your wireless home network or make your wireless network cover everywhere in your house even if it uses metal-based energy-efficiency measures or has thick brick or stone walls.

 

 

Feature Article: Making Sure Your Home Wireless Network Is Secure

This Christmas, you may have received a new wireless Internet router as a Christmas present and are eager to dabble in the joys of wireless “hot and cold running Internet”. You will need to make sure that this network is operating in a secure manner in order to stop unknown and unaccounted use of your bandwidth allowance and to stop others from raiding your household’s private data. This is as essential as making sure that your home is physically secure through your use of deadlocks and intruder alarm systems.

Most likely, you will have implemented computer security measures like installing and using a desktop firewall and desktop virus-control and spyware-control utilities. You will also have deployed a spam-control utility on your e-mail inbox or signed up to a spam-filter service provided by your ISP.

Getting started on making your wireless network secure

Use the “Getting Started” leaflet for your router to identify how to configure it. You may have to run the CD that was supplied with your router and will need to connect your computer to it using the Ethernet cable that should have been supplied with it.

Windows Vista

Those of you with Windows Vista who have routers marked with a “Certified for Windows Vista” logo may find this job easier because the operating system will discover the router and put up a prompt at the right hand side of your screen upon power-up. You may have to click on “Control Panel”, then “Network and Internet”, then click on “Connect to a network”.

Next click “Set up a wireless router or access point” and click “Next” twice. Windows will interrogate your router and if it can’t be configured through Windows Vista, you will see a window which offers two options – “Configure the device manually” and “Create wireless network settings and save to USB drive”. Click on the first option to open the wireless router’s configuration page. If you just unwrapped it, you will need to use the default password printed in the router’s documentation.

Also, click on the second option to prepare a configuration set for your router. With this wizard, you will need to create an SSID and WPA network security key. Work through the wizard and choose a network name (SSID) that is peculiar to your premises and transcribe this SSID. Then click “Next” and accurately transcribe the passphrase written in the wizard.

Put a USB memory key in the computer then click Next. When the screen darkens, click “Allow”. Choose the situation appropriate to your network. If your network is already established, select the “Custom settings” option and click “Next”. Then click “Close”. You have created a master configuration set for your wireless network and that is now stored on your USB key.

Go back to the wireless router configuration page that you opened before in the second paragraph and go to the Wireless Network option. Copy the SSID into the “SSID” or “Wireless Network Name” box. Then go to the Wireless Security box and set your router to WPA-Personal and copy the WPA network security key into the passphrase box. At this point, go to the administrator password option and change the administrator password to something that you remember but is secure.

Windows XP SP2

If you don’t have the “Getting Started” leaflet on hand, connect to the router as described before and type “cmd.exe” in to the Run prompt. This is accessible by pressing [Windows| and R together on the keyboard. Then type “ipconfig” in to the command prompt. Look for the “gateway address” and note it down. Then use your Web browser to log in to the router.

Opan Control Panel and click on Wireless Network Setup option. Enter an SSID (wireless network name) that is peculiar to your premises and select “Automatically assign a network key”. Tick Use WPA encryption instead of WEP and click “Next”. Select “Use a USB flash drive” and click Next to copy the details to a USB memory key which you have inserted in your computer. Select the drive letter that corresponds to the USB memory key. Click “Next” to copy the details to your USB memory key.

Windows Vista, Windows XP SP2

“Dip” the USB memory key into the USB port on any Windows XP SP2 or Windows Vista computer with a wireless network ability that is part of your network and select the Wireless Network Setup Wizard option on the AutoPlay dialog box.

Apple MacOS X, UNIX (Linux)

Put the USB memory key in to the computer and open the SMRTNTKY folder. Open the WSETTING.TXT file and copy the SSID and WPA network key in to your wireless network configuration utility. In the case of the MacOS X, make sure that it is part of your “keyring”. Then dismount and remove the USB memory key.

All operating systems

Then put the USB memory key in to a computer attached to a printer and click on the “Open Folder to view files” option  Open the SMRTNTKY folder and click on WSETTING text document (WSETTING.TXT) . Print this document out and keep it in your files. This is of importance for when you connect up newer wireless network devices.

Feature Article: Multi-Building Home Networks

What is a multi-building home network

A multi-building home network is a home or other small network where network devices are used in at least two buildings on the one property. The idea is for the whole logical network to be pervasive in all or some of the buildings that are on that same property.

The network will end up comprising of multiple segments (physical network connections) that cover each building where network presence is desired. Then there are segments that exist to create a bridge for data to move between buildings.

What properties and situations is this kind of network relevant to

The situation where this network comes in to its own is where it is desirable to have the home office in another building such as a detached garage or barn, but also the same Internet bandwidth needs to be available in the home and the detached building. This is more prevalent with farms where the “office” is the barn and none of the farm business is transacted in the homestead.

The same situation can exist with properties where there is at least one cabin, bungalow or static caravan that is used for extra guests or older children. Here, it may be desirable to provide the same Internet access as what exists in the main house to these locations. This is important with older children who use these buildings as their private space for activities including playing online games. In a similar vein, the same situation may extend to the use of a cabana that is located by the pool or in the garden as a place to benefit from Internet access through the use of a portable computer.

Now that various manufacturers are making network appliances like Internet CCTV cameras or Internet-enabled games consoles that benefit from being part of a network, this concept of multi-building home networks is becoming a lot more relevant. Imagine being able to keep an eye on the valuables in the garage or livestock in the barn from a PC in the house; or the older son playing an on-line game on the Xbox 360 using XboxLive in the bungalow.

How does this kind of network operate

This kind of network consists of many different segments that exist to cover the areas being served as well as segments that exist to transfer data out to the area-specific segments. All the segments are joined using media-specific bridge devices like wireless access points, Ethernet switches, HomePlug-Ethernet bridges or simply the local-network connections of the typical wireless router.

This means that all network devices that are part of this network setup are on the same logical network or subnet. This means that if they ask for IP addresses,  they will get their IP addresses from the same DHCP server that is in the network-Internet “edge” router. They will also benefit from that router’s Internet gateway functionality and from resources made available to them by other network devices.

Techniques And Methods

Dedicated wire run 

The buildings may be linked by a direct wire, usually Category 5 / 6 twisted-pair copper Ethernet cable or fibre-optic cable. The fibre-optic cable is more expensive than copper-wire cabling, especially for smaller runs, but would suit installations where the buildings are a very long distance (3 kilometres) apart or there could be excessive electrical noise. On the other hand, copper-cable twisted-pair Ethernet can suit inter-building runs of up to 100 metres.

Both cables will need a dedicated run, which will typically require a trench to be dug between the buildings and the cable to be run in a conduit for best results. This work can be affordably done if you are running low-voltage communications cable like a telephone line between the buildings.

Each end of the cable run would need to have an Ethernet switch in the case of a copper-cable run or media converters in the case of a fibre-optic run. The Ethernet switches are just about a “dime a dozen” for a five-port or eight-port unmanaged 10/100Mbps unit suitable for small networks and a bit extra for Gigabit units. An existing switch that is part of your home network, such as the one built in to your router or used as a “hub” in your Ethernet-based home network can do the job equally as well as a dedicated switch. 

Wireless

This method uses a radio link as the means for data-transfer between the buildings. It is based on the use of 802.11a/g/n equipment, commonly known as WiFi equipment, which works at a theoretical raw data speed of 54Mbps for 802.11a/g and 248Mbps for 802.11n. The range where the speed will be maintained will depend on the wireless equipment used and the antennas (aerials) used with the equipment. Typically the bandwidth will taper off as the distance between the equipment increases.

Inter-building applications have typically used equipment that is capable of working with higher-gain directional antennas than what is typically supplied with the equipment and such equipment is typically installed outdoors with an Ethernet cable used for bringing data in to the buildings.

It can involve the use of “shared WiFi” where remote buildings are equipped with wireless client bridges that are pointed towards the wireless access point installed in the main building. This same method permits WiFi use by portable devices used in or near the main access point, but requires different SSIDs for access points used in remote buildings.

Another method is to use a dedicated wireless link for building-building data flow. This can be achieved through the use of multi-function access points that are set up as “wireless bridges”. This wireless link wouldn’t be able to be used by portable devices for wireless network access.

Yet another method that works with some wireless access points and wireless routers is to use Wireless Distribution System. It allows the member devices to become wireless-segment repeaters, thus expanding wireless segment coverage and becoming an Ethernet bridge for the data. Portable devices can roam amongst the stations as if they are moving around an “extended service set” collection of access points with a wired backbone.  At the moment, the setup doesn’t permit true fault-tolerant signal meshing without bandwidth starvation, but can do a fair “hands-off” job of extending the “extended service set”.  

Non-dedicated wire run 

This method uses wires that are used to provide an existing service to the building rather than a dedicated wire run. It avoids the need to spend money on costs associated with running that dedicated wire, such as trenching and conduit runs, while avoiding the need to dig up established landscape.

There used to be two methods based around this concept but the most common one would be the HomePlug system which uses the infrastructure that is used to provide AC power to appliances that are used on the property. It is often marketed as a “no-new-wires” backbone for establishing new networks but can be used as a supplementary segment for existing networks. This is typically promoted through the small “infill” access points like the Netcomm NP290W which plug in to the wall and provide extra coverage for an existing wireless network.

It can work effectively in most residential, small-office and rural properties because they are often wired to the one general-purpose electricity service from the head transformer. This is typically exemplified with the property having one “common-tariff” electricity meter accounting for all the “common-tariff” electricity used on the property. It may not work if any building, like a bungalow, has been metered separately because, in most situations, the different services may have been derived from different phases.

Some sites may, because of inter-building wiring distance, require the HomePlug segment to be pushed out further. This situation is typical of buildings that are used as a “go-between” wire point for other buildings or static caravabs. This involves the creation of extra HomePlug segments for the remote buildings.

This is achieved by the use of 2 HomePlug-Ethernet bridges connected to each other by an Ethernet patch cord or Ethernet switch and installed close to the building’s AC switch board or fuse box.

One of the bridges is configured to use the Network Password (segment identification name for a HomePlug network, equivalent to an SSID for a WiFi wireless network segment) of main segment, while the other uses a new Network Password representative of the new segment. Remote HomePlug devices use new Network Password.

The appropriate method

Working From Scratch

You may be building the outbuilding from scratch or doing extensive renovations to an existing building, which involves work with the electrical circuits in the building. This includes running AC wiring to and establishing AC circuits in an existing building that has no AC power. In this case, you may want to “cover all your bases”, especially if you are dealing with a garage, barn, bungalow or cabin where the building is going to be a point of activity. This means running a dedicated wire run between the main building and the outbuilding. The materials that you use may depend on your budget that you allocate for the project.

This option can work very well in making maximum value from your tradesmen who are doing any cabling work on the project. If cost is an issue, you may have to use HomePlug as your inter-building link.

Existing Buildings

For existing buildings, especially on properties where there is established landscape, you will need to use either a wireless or HomePlug link.

If you prefer to run a wireless link, it may be preferable to use wireless infrastructure hardware which works with third-party antennas and is capable of working outdoors.

HomePlug can also and has been known to do a more reliable job as a building-building link in this context than wireless. This is more true of buildings that are made out of metal such as the “quick-assemble” garages and sheds because the metal frame and / or walls do block or limit the transmission of radio waves.

Static Caravans

Typically these vehicles are capable of being moved around the property at a moment’s notice. Most of the time, these vehicles are hooked up to the nearest power outlet on the property using a long high-current low-resistance extension cord. This is often to enable use of interior lights and appliances that are plugged into power outlets that are installed in the vehicle. Also, this practice allows one to use the gas-electric fridge that is built in to the vehicle with it running off AC power rather than gas or the vehicle’s 12 volt battery.

A highly-reliable method of bringing the home network to these vehicles would be the HomePlug power-line link. This technology would be suited to the job because of the metal-based construction of the typical post-1950s caravan or campervan which can interfere with wireless inter-building links. The HomePlug access points like the Netcomm NP290W can work effectively in this situation by providing a strong wireless signal within the metal walls of these vans while using the power link as the data run.

Conclusion

As governments and Internet service providers make an effort to provide less-dense communities like the country and outer-urban areas with broadband Internet access, the idea of extending the home network beyond the main house on a large property will be very real. This article has explained how this idea can be achieved with the existing technology.

DLNA-compliant media software for the Apple iPod Touch and iPhone

http://cgimediasuite.sourceforge.net/ – Link to web site for the iPhone / iPod Touch UPnP AV / DLNA software

CyberGarage have released two programs that bring the Apple iPhone and iPod Touch into the UPnP AV / DLNA home media network environment. This is certainly in response to many Google searches for software that can pull off this function on these popular and trendy devices.

The first one, iNetFrame, is a network picture viewer that allows the user to view pictures in an online collection hosted on the Picasa or Flickr photo-sharing sites. But this one allows one to view pictures on any UPnP AV / DLNA server on the local network. This program makes use of these resources to turn the iPod Touch or iPhone into a network electronic picture frame with an optional clock display.

The other program, iMediaSuite, works as one of three functions:

· a media server for media files held within the iPod Touch or iPhone;

· a media viewer which allows one to view or listen to media files held on other DLNA media servers; or

· a control point for playing media collections held on any DLNA media server (including itself) through another UPnP / DLNA media client that supports external control.

There are some obvious limitations with this software, such as being able only to play the file types that the iPhone or iPod Touch support, and not being able to play Apple FairPlay DRM-protected files on any of the DLNA media devices out there. This doesn’t affect the program’s use as a control point if you are playing files on another DLNA device from another DLNA collection. At least this is the first step in bringing the Apple iPhone world towards the DLNA media network.

One application that I certainly would admire is the control-point function because it avoids the need to have the TV on if you are playing music on one of those many network media adaptors which don’t have any display on them. You can just “point to it to play it” on the iPod Touch or iPhone.

Apple iTunes App Store locations:

iMediaSuite : http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=293809842&mt=8

iNetFrame : http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=294937127&mt=8