Category: Network Management

Introduction

Now that the 802.11n high-bandwidth wireless-network standard has been declared a final standard, the price of 802.11n-compatible wireless-network hardware will come down to more affordable levels. This will lead to you considering upgrading your wireless network to 802.11n whenever the time is right to renew your home-network IT hardware.

The 802.11n access point

This works in a different manner to the 802.11a/b/g access points we are so used to. Basically, these units use a “multiple in, multiple out” methodology with “front-end diversity”. They will typically have two or three aerials with each aerial serving a particular transceiver. Some units may have an aerial serving a receiver as well as the two aerials serving two transceivers. It is totally different from “antenna diversity” which is used on most 802.11b/g routers and access points, where one transceiver works with two aerials, choosing whichever has the best signal strength.

These access points and the network client devices that connect to them also make use of “constructive multipath” to improve their quality of reception.This is different from the “destructive multipath” often experienced with FM radio and analogue television. Here, signals picked up as reflected signals are mixed with signals received by line-of-sight and “worked out” as a data stream.

The premium-priced 802.11n access points will be typically dual-band in which they can work on the existing 2.4GHz band or the newer 5GHz band. Some of this equipment may be able to work on both bands, as though there are two access points in one box.

Access Point Types

Single Band

These access points use a single access point that is set up to work on one band, typically 2.4GHz, but some of them work on 5GHz as an “add-on” access point.

Dual Band, Single Radio

These access points are like a single-band access point but can be set by the user to work on either 2.4GHz or 5GHz, but not both of the bands.

Dual Band, Dual Radio

These access points, sometimes described as “simultaneous dual-band”, are effectively two 802.11n access points in one box with one working on 2.4GHz and the other working on 5GHz.

Access Point Operating Modes

Primary Operating Modes

A typical 802.11n access point can be configured to work in one of two primary operating modes – a “compatibility” mode or an “N-only” mode.

Compatibility Mode

This mode, known as Mixed Mode or G-compatible mode allows 802.11g wireless network hardware to work from the same access point alongside 802.11n equipment. The limitation with this mode is that the wireless network works to a “worst-case” scenario with throughput that doesn’t hit the standards for an 802.11n segment. You will still have the larger coverage and service reliability with the 802.11n equipment and this benefit may pass through to 802.11g equipment

N-only Mode

This mode allows the access point to work only with 802.11n equipment and gives the equipment full wireless throughput as well as the full reliability of the standard.

Wideband vs Standard Channels

802.11n access points can run their channels as either “standard” 20MHz channels or 40MHz wideband channels which can yield higher throughput. The wideband channels also make use of a “standard” channel as a “base” channel for the double-width channel.

The preferred method of operation is that a 2.4GHz access point works on “standard” channels and most such access points will be set to have this kind of behaviour by default. But you can run these access points on the wideband channels with the limitation of poorer compatibility with 802.11g devices. If you are running a 2,4GHz access point in a manner to be compatible with regular 802.11g devices, it would be a good idea to stick to “standard” channels. If you are running 5GHz access points, you can get away with using the wideband channels and I would prefer setting up a 5GHz 802.11n extended-service-set to work this way.

The number of streams a device can handle

An 802.11n wireless device will typically be rated as being a single-stream, dual-stream or multiple-stream device. This relates to how many streams of data the wireless device can handle. All Wireless-N (802.11n) access points and routers will typically be either a dual-stream type or a multiple-stream type in the case of premium devices. Similarly, laptops with integrated Wireless-N capability; and add-on Wireless-N products will typically be dual-stream devices.

The main class of devices that will handle only one stream will be primarily-battery-powered devices like smartphones, WiFi VoIP phones, and WiFi-enabled digital cameras / portable media players because the single-stream ability won’t be intensive on these devices’ internal battery resources. Similarly, the idea of a single-stream Wireless-N network interface will also appeal to applications where size or cost do matter.

Other points to know

Best practice with dual-band equipment

If you are running dual-band equipment, especially dual-band dual-radio equipment, it would be a good idea to use the 5GHz band as N-only mode, while 2.4GHz works as compatibility mode. If you are running dual-band single-radio equipment, you will need to use older 2.4GHz equipment to run an 802.11g service set with the dual-band single-radio equipment on 5GHz N-only mode.

Use of aftermarket antennas

You can use external aftermarket antennas (aerials) with 802.11n equipment as long as all of the antennas are of the same type. This may work well if you replace the omnidirectional whip aerials with stronger omnidirectional ones. Then you may have to space the aerials further apart for the front-end diversity to work properly The main difficulty you will have is using directional aerials, in which case you may need to look for directional aerials optimised for 802.11n setups.

As well, if you are running dual-band dual-radio equipment, you will have to use antennas that can work on the 2.4GHz and 5GHz bands rather than antennas optimised for the 2.4GHz bands.

Shaping your 802.11n wireless network – the ideal upgrade path for your wireless network

I will be talking of WiFi networks that work on a particular technology and with a unique SSID and security parameter set as an “extended-service-set”. This allows me to cover setups where there are multiple access points working with a particular configuration.

You may be tempted to construct a multiple-access-point extended-service-set with an 802.11g access point and an 802.11n access point working in “compatibility mode” connected by an Ethernet or HomePlug wired backbone. The simple answer is "don’t”. You will end up with your wireless network having reliability problems especially as devices roam between the different access points and switch operating modes.

The simple answer would be to run different extended-service-sets with at least one access point for each WiFi technology. They are set up with different ESSIDs (such as SSID for the G cloud and SSID-N for the N cloud) with the wireless stations choosing between the different ESSIDs. The only thing they can have that is common is the WPA security parameters, and a common wired backbone which can be Gigabit Ethernet or HomePlug AV.

This could be achieved through deploying an existing 802.11g router that is set up as an access point and working on “SSID-G” and one channel while a newer 802.11n router working as the Internet “edge” is set to “N-only: or “compatibility” mode in the case of a single-band 2.4GHz unit, and set to “SSID-N” and a different channel.

As you evolve your wireless network, you may want to work towards establishing a 2.4GHz 802.11n “compatibility-mode” extended-service-set and a 5GHz N-only extended-service-set. You then upgrade your portable computers to work with dual-band 802.11n network interfaces or add dual-band 802.11n network adaptors to your existing equipment. The 5GHz extended-service-set will come in handy for high-throughput activity like video streaming and related applications while the 2.4GHz extended service set can work well with voice applications, smartphones, Internet radio and similar applications where throughput doesn’t matter.

If you are upgrading a wireless hotspot to 802.11n, it would be preferable to make sure your hotspot’s extended-service-set is on the 2.4GHz band and operating in “compatibility” mode so that customers can still use their existing 802.11g hardware on the wireless hotspot.

Some issues may occur with dual-band networks where the 5GHz extended-service-set may not cover the same area as the 2.4GHz extended-service-set. This is because the 5GHz band is of a higher frequency and shorter wavelength than the 2.4GHz band and is best demonstrated by AM radio stations being receivable at a longer distance compared to FM radio stations. It can be rectified by deploying a dual-band single-radio access point working on the 5GHz band in to the 5GHz extended-service-set as an infill access point.

Conclusion

Once you understand the 802.11n wireless standard and what it can and cannot do, you can make sure that you get the best out of the new standard while gaining the maximum mileage out of the existing wireless-network hardware.

Peugeot intègre le Wi-Fi dans ses véhicules | DegroupNews (French language)

Chrysler confirms in-car Wi-Fi coming next year | Engadget

BMW’s ConnectedDrive brings the whole internet to your car… on EDGE | Engadget

There is a new trend concerning the small network in that the car will have its own IP-based network with a link to the Internet. This has been brought about by manufacturers making WiFi “edge” routers with a 3G wireless link on the Internet side for installation in vehicles. Similarly vehicle builders like BMW, Chrysler and Peugeot are using this feature as a product differentiator in some of their vehicle models.

But what use are these devices?

Primarily these devices provide Internet access to passengers in minivans, limos and the like; and some bus fleets are taking this further for provision of Internet access to their premium routes. Some people may also think that these routers may have the same appeal as the “component-look” car stereo systems of the late ‘70s and early ‘80s; where they only appealed to young men who were customising cars and vans in order to impress others.

What could they offer

Like the typical home Internet-edge router, all of these routers offer Ethernet and WiFi for the local network connection, which means that car devices can be directly connected to these Internet gateways. This can lead to online applications being made available to integrated or aftermarket-installed equipment which is being considered as sophisticated as a typical personal computer.

Ethernet port on the car stereo

A car stereo system could have an Ethernet port and support the same kind of network media services as some of the in-home entertainment systems offer. One application could be Internet radio functionality, where the set could have access to the Frontier Platform, Reciva or vTuner Internet-radio directories; and be able to pull in Internet radio from around the globe. An idea that may come to mind is the concept of young men “cruising” along Chapel Street in South Yarra; Campbell Parade in Bondi; Surfers Paradise or other “show-off” streets in Australia or coastal USA with the dance grooves from Heart London’s “Club Classics” program thumping out of the “subs and splits” in their souped-up machines during a special UK long weekend. Another function would be to support the “visual radio” platform that is part of most mobile-phone FM-radio implementations.

Another more interesting application is an in-car DLNA media network. The 3G WiFi router could work as a WiFi client when, in the presence of the home network, cause syncing of content between the home DLNA media network’s server and a hard disk built in to the car stereo. This allows for newly-added music content from the home network and up-to-date podcasts to be available in the car.

Similarly, there could be the ability to play content held on a DLNA-capable WiFi-enabled mobile phone or portable media player through the car speakers. As well, a small NAS like the Thecus N0204 miniNAS which I have mentioned about in this blog could be shoehorned to work from a car’s power supply and become a DLNA-enabled media storage unit for the car.

This functionality can be extended to the back seat in the form of access to newer video content from the home network or access to online video content to the back screens. As well, the vehicle’s music system could work as a DLNA media server for use in providing media at secondary locations like holiday homes or worksites. This would be in conjunction with a DLNA-compliant media player connected by a WiFi segment between the vehicle and the building’s network.

There is more information about how DLNA is investigating implementation of this standard in the automotive context in this white paper (PDF) at their website.

Ethernet connection for navigation systems

The “sat-nav” systems can benefit from Ethernet connectivity for integrated units or WiFi connectivity for portable navigation devices. This could allow for these systems to have up-to-date information about new points of interest as well as another link for receiving real-time traffic information.

The IP feed can work very strongly with real-time information being received from the wireless Internet in order to provide updated traffic information and / or real-time service information for garages, restaurants, motels and the like. This will then allow drivers to make better decisions about their journeys such as alternate runs or use of services. It could cater for “social recommendation” functionality for the roadside services so one can go to where the food’s known to be good for example.

Support for IP-driven vehicle telemetry

The vehicle could have an Internet-based direct link to the garage that the owner has a working relationship with, or to the fleet-management service in the case of a vehicle that is part of an organisation-owned fleet. This link can allow access to historical diagnostic information about the vehicle thus allowing for informed decisions concerning what repair work needs to be taken or whether the vehicle should be pensioned off.

Similarly, there could be the ability to implement vehicle / driver surveillance techniques which can be of benefit to parents of teenage drivers or organisations who need to keep in step with workplace safety or professional-driver regulations.

In some cases like public and community transportation, it may be desireable to have IP-based closed-circuit TV surveillance that streams the vision “back to base” instead of or as well as recording it to a local hard disk. This will also please the police force where officers are in a “first-response” situation and need “many eyes and many brains working together” on an emergency situation.

Electric vehicles (including hybrid-electric vehicles)

These vehicles will typically benefit from network and Internet connectivity in order to permit flexible power management situations like optimised battery charging or vehicle-to-grid setups. They will also benefit from the above-mentioned IP-driven vehicle telemetry so that the user or preferred mechanic knows if the battery is not holding its charge in the same way that it used to, thus knowing when to have it replaced.

What needs to be done

I would prefer the in-vehicle network to be capable of working as its own network with a 3G or similar-technology WWAN as proposed by the vehicle builders in their implementation or as a member of user-selected WiFi LANs in a client / access-point (WDS) role. This can be determined by a list of “preferred” SSID / WPA(2)-PSK combinations held local to the vehicle.

The “Ethernet behind the dash” concept of using Category 5 Ethernet to create a wired LAN amongst in-vehicle subsystems has to be researched, This includes how Category 5 Ethernet can handle the problems associated with an automotive electrical system which is known to be very noisy or prone to surges and spikes such as while the vehicle’s engine is being started.

Once the concept of the automotive local area network is researched properly, there is the ability to use it as a simple data conduit across vehicle systems for all data-transfer applications, not just for Internet surfing by passengers.

IEEE finally approves 802.11n | The Register (UK)

802.11n: Ratified at last | Wi-Fi Planet

IEEE Ratifies 802.11n | WiFi Networking News

The Fine Points of Optional Wi-Fi 802.11n Certification | Wi-Fi Networking News

My Comments On This Evolution Of The Standard

Ever since 802.11n came about as a wireless standard, the equipment that was working to the standard was working to a draft version of the standard. This may have been acceptable for networks which weren’t critical to a business’s operations, because of the doubt associated with last-minute changes that could affect hardware compatibility. In some cases, this could also mean that an 802.11n segment may not work properly unless the equipment was based on the same chipset.

Now that the standard is final, enterprises can become confident about deploying 802.11n wireless network segments with cost-effective heterogenous equipment setups. As well, the cost of establishing an 802.11n wireless-network segment will reduce now that manufacturers can confidently sell more equipment at varying price ranges.

Existing 802.11n draft-standard segments

But what does this mean for networks based around existing 802.11n draft-standard hardware? Could they work properly with final-standard hardware with as much as draft-standard hardware being “flashed” to final-standard specifications. The compatibility issue raised in this question has been through the new revisions being declared optional rather than mandatory.

Support for single-stream 802.11n devices

The most popular benefit of the new standard would be the ability to support single-stream 802.11n station devices. This concept allows a device to have one transceiver rather than the two or three that is part of the standard. It is mainly brought about because of a need to have battery-operated devices like smartphones and VoIP WiFi handsets as part of the 802.11n wireless network and the single-stream 802.11n network adaptors can fulfil this need without draining the device’s battery too quickly.

The access points can provide full bandwidth to these single-stream devices without forfeiting bandwidth to other devices simply through the use of one dedicated stream for each of the devices. It then may be like providing the wireless equivalent of a “switched” Ethernet connection or ADSL-based broadband connection to this class of devices.

This factor has been improved with the ability for access points to be tested for three streams. This may allow for access points and routers to be differentiated on wireless-network performance levels as well as functionality levels.

Conclusion

The goal has been achieved for 802.11n to be a real wireless-network standard that complements the high-throughput Internet services and the multimedia networks of today.

Today, I had seen some excellent YouTube videos posted by Netgear on how to integrate your games console in to your home network. They make references to the networks being based on their own hardware, but these instructions apply to any and all home networks no matter what router is at the edge.

Also, when they discussed how to connect the XBox360, PlayStation 3 and Wii to the home network, they mentioned that you can use a HomePlug-based power-line network setup using their PowerLine AV network kit to build the HomePlug segment. The main theme was to connect the HomePlug adaptor to the console via its Ethernet port and select the “wired” connection option as appropriate.

The reason I have liked the videos was because they gave a visual walkthrough of the setup user interaction needed to be performed at each console. They also pointed out if a console needed extra hardware to be part of the home network depending on the connection type. They are also worth having as a reference if you are likely to move your console(s) between locations such as for video-games parties.

If you are viewing this in an RSS Web feed, whether through your RSS software or as syndicated content on a Website like Facebook, you will need to visit this blog to view the videos. You can do this by clicking on the View Original Post option in the software or Web site. 

TV-connected consoles

Microsoft XBox360

Sony PlayStation 3 (PS3) – includes “PS3 Thin”

Nintendo Wii

Handhelds

All of these handheld have integrated WiFi as their sole connection means due to their portable nature.

Sony Playstation Portable (PSP)

Benefits: Online Gaming, Web Browsing, RSS Feeds and Podcasts

Nintendo DSi

Benefits: Online Gaming,Game download via DSi Store, Web browsing

 SmallNetBuilder – Small Network Help – 802.11n Headed for September Ratification

Cited text from SmallNetBuilder article

SmallNetBuilder has learned from a reliable source that the final issues in 802.11n have been resolved in this week’s meeting of the IEEE TGn in Montreal.

The draft standard is now expected to successfully pass through the final steps required for a ratification as a final standard in September. This is four months earlier than the currently published January 2010 date.

The key issue holding up the standard has been the mechanisms to be used to prevent interference between 802.11n and Bluetooth devices.

My Comments on this stage for 802.11n

Once this standard is ratified, most of us can now buy 802.11n-compliant wireless-network hardware while being sure it will work with other manufacturers’ equipment.

But the main issue with this ratification is whether most hardware manufacturers will roll out firmware for existing draft-specification 802.11n hardware that is in the field. This is of importance whenever newer final-specification hardware is deployed, because there could be compatibility issues between the different versions of the standard.

A good step to go about this is to go to manufacturers’ Websites and look for upgrade packages for any 802.11n hardware. In the case of laptops, use the laptop manufacturer’s Website or “quick-update” routine to check for updates for the wireless-network subsystem. If you run an “n-box” or other equipment serviced by your Internet service provider, check with the provider if there is new firmware in the pipeline for the hardware. This may be dependent on whether the device’s manufacturer is rolling out compatible firmware for provider-distributed devices.

In some cases, you may need to run your 802.11n wireless network segment on a “mixed” setup which observes best compatibility with 802.11g devices even if the segment is running only with “n” devices.

 Network Connectivity Joins the AV Club | ABI Research

Cite from press release

Over the past few weeks, a couple of announcements around consumer electronics connectivity have caught my eye. In late April, the DiiVA Interactive TV standard was announced after a year of development, with the backing of mainstream CE manufacturers LG, Panasonic, and Samsung, along with the Chinese government and a number of major Chinese CE manufacturers. The DiiVA standard was designed to integrate HD Video, multi-channel audio and bi-directional data (Ethernet and USB) in a single cable. Then, just last week, the HDMI Licensing group announced the HDMI 1.4 specification, which will integrate Ethernet connectivity within the HDMI cable.

My Comments on this concept

The concept behind the DiiVA stamdard and HDMI 1.4 is to cut down the “spaghetti junction” that exists behind a home-entertainment system by avoiding the need to run an Ethernet cable between each Internet-enabled AV device and the home network.

The current problem is that most Internet-enabled equipment that is in the field will require use of a direct network connection, typically an Ethernet cable, even if the AV setup includes equipment that has the new connections. As the standards gain traction, users will have to work out which component will be the interface to the home network; and some equipment will need to always have a direct connection to the home network as well as support for Ethernet connection via the new standards.

When the standard reaches momentum, I would still prefer that certain classes of equipment always have an Ethernet socket or MoCA/HomePlug AV interface. Primarily, I would require that a television set (with built-in TV tuner); and a surround-sound receiver would have the home-network interface. Similarly, I would require that devices performing the role of a surround-sound receiver like “home theatre in box” systems and single-piece “soundbars” be equipped with the home network connectivity. This is typically to allow one to assure network connectivity to all consume AV-equipment setups that use these connections, as these setups evolve. Some AV peripherals like optical-disc players or games consoles may just rely on their network connectivity coming via the AV connection.

Another factor that needs to be worked out with this connection setup is making sure that the network-enabled AV setup just works. Issues that can impede this ideal could include “network collision loops” where devices that are directly connected to the home network and are interconnected with network-enabled connections create an infinite data loop. This can lead to extensive operational and performance difficulties, similar to when a laptop is connected to a WiFi router with an Ethernet cable while its WiFi network functionality is active. This issue could be addressed by the use of a priority-based algorithm for determining the data flow in the AV setup.

Once these issues are addressed, these connection standards should then lead to trouble-free network-enabled home AV for all setups no matter how sophisticated they are. Similarly, this could lead to such concepts as the AV devices providing extra network services such as in-fill WiFi access points or Ethernet switches.

W7 RC Secure WMP Internet Streaming is Impressive | DigitalMediaPhile.com
– further details on handling of network connection speeds

Windows 7 Enables Secure, Remote PC to PC Streaming via WMP and Windows Live ID | eHomeUpgrade

My comments on this feature

There are certainly a few key applications for this feature.

One main and obvious application would be to gain access to music, pictures or video held at home from a remote location like the holiday home, car or small business. This would be achieved through the use of technologies like 3G or WiMAX wireless broadband; or simply ADSL broadband depending on the location.

Another application similar to what Barb Bowman was using as her demonstration setup in the articles she had posted on this feature is a household with two or more individually-controlled Internet services. This may be a student or other person who is paying board and lodging to you; a live-in housekeeper or nanny; or an elderly or disabled relative or friend who needs continual care. These people may want to operate a separate Internet service that is under their own control but may want to annexe both the primary household’s and their own media resources.

But. as with any new technical implementation, there are questions that need to be asked

Could this setup work over a VPN such as one used to facilitate remote access to a small business’s data? This setup may be of benefit to a shop or small office where some of the music or pictures used as part of merchandising at the business may be held on the home computer.

Could this allow a UPnP AV / DLNA device to pull up media from the remote location via the Windows Media Player “gateway”? In this setup, a DLNA-compliant Internet radio installed at the remote location points to the UPnP Media Server that is part of the remote computer’s Windows Media Player. This would be pulling up media from the local computer’s Windows Media Player setup as in your described installation.