Wireless Networking

From TheBestCaseScenario

[edit] Wireless Networks - The Absolute Basics

There are two main communication networks we rely on and which are merging. One is the Internet and the other is the telephone network. Telephone networks are increasingly being built around computerised switches and IP or Internet Protocol standards. TCP/IP is the basic standard devices on the Internet - including your computer - use to exchange information with each other.

Information is processed through several layers and ends up being split into packets which are sent from end to end - not necessarily arriving in sequence or via the same route - then reassembled into the original data at the receiving computer when it all arrives.

Your home network is an extension of this system. Wireless networks send packets - usually between your computer and a router or wireless access point plugged in to a router. The exception is a peer to peer network - where you have two computers communicating directly with each other rather than through a router. You can do this to share the internet connection on one machine with that on another if you only have two computers you want connected. The upside is it is really cheap - but then so is all wireless networking equipment today - and the downside is the machine hosting the Internet connection has to be on for the other to connect and may show some minor deterioration in performance.

[edit] Standards

Without going in to too much detail about all the technicalities of every stage of development, it is important to understand some differences between the various Wireless Networking standards that have been developed or are in use. They all fall under the standard of the Institute of Electrical and Electronics Engineers, or IEEE, standard 802.11 and there are three that matter here:

802.11b

The first generation of equipment to gain popular use and deployment were based on the .b standard. It can operate at up to a nominal 11Mb/s giving actual throughput of up to around 6 - 7 Mb/s. This is faster than most residential broadband connections today but not for long.

802.11g

The second generation specification to see widespread deployment and acceptance .g offers increased speed, range and security (see below) over .b giving a nominal 54Mb/s connection and throughput of a little over half that in reality.

802.11n

Although officially not finalised as a specification and therefore subject to change and review, .n equipment is already on your local high street or website. The WIFI alliance have been certifying equipment based on the draft n specification since 2007. The great advantage is the multi antennae broadcast and receive system which means much greater throughput and range.

The difference between n and g: n will deliver throughput of 74Mbits/s up to 250M outdoors, againsts g's 19Mbits/s up to 140M outdoors.

Compatibility

A .b spec router will operate with most .g spec network cards and vice-versa but only at .b speeds. The same will be true for n spec equipment - backwards compatibility is built into the system. Some routers will work in mixed-modes whereby some devices can connect using the .b standards and others using the .g standards. There have been mixed results and if you intend to do this it is worth researching equipment known to work well in mixed mode. Be warned that the general result of mixing equipment is poor performance.

[edit] Equipment

Base Stations

Wireless Routers

A router is a device that sends network information to the device that the information is intended for/has been requested by. Wireless routers usually offer a mix of wired (Ethernet) connections and wireless connectivity. A wireless router will need to be plugged into another device that make the connection to the internet using an Ethernet cable - a modem or cable-modem for example. The router then takes the information arriving at the modem and then distributes it to the computer that asked for it.

Wireless Modem/Routers

These devices are basically the same as wireless routers but also perform the modem function, connecting to the internet via your Internet Service provider. There are different types available for different types of cable and telephone network so make sure you tell the sales assistant exactly what sort of internet connection you have before buying.

Wireless Access Points

Wireless Access Points add wireless functionality where you already own a non-wireless capable router. The access point is plugged into the router and configured, usually using a web interface, by your ethernet connected PC.

Receivers

Network Cards/Adapters

Network Cards or Network Adapters are the client (computer) side of the wireless network equipment. They send and receive signals between the computer and the wireless router or access point. They come in three types:

Laptops

Most laptop computers more than a few years old have Wireless capability built in. You may want to add a USB adapter one to get better reception in weak signal areas.

PCI

PCI adapters are fitted inside desktop computers. Sometimes the software gets installed first but usually the card. Read the instructions. There is a wiki for fitting PCI cards here * Installing PCI Cards

USB

USB adapters plug into a USB port on the PC or laptop. The cheaper ones don't seel to work too well. There is often a USB bottleneck if you have many USB devices connected. However they do offer the benefit of being able to be located in a position where there is a stronger signal, away from monitors and PC's that create a lot of electrostatic interference.

[edit] Setting Up Your Home Wireless Network

You will need a wireless router or router/modem or a router and a wireless access point and network cards/adapters for each machine that is going to connect wirelessly.

The router/access point will usually need to be configured using a machine connected to it by an ethernet cable, in the first instance. Once everything is up and running however there is no need to have any computer connected by cable. Your whole home network can be wireless.

Set up the router or access point first. Make a note of any encryption keys you create and the SSID. you will need these to configure the receiving computers network cards/adapters.

Sorry this is really lame but, read the boxes and manuals and stuff for the equipment you have. They usually tell you what to do more easily than a wiki can for particular equipment. However before you launch into setting up your network read the rest of the information below on security. You do want to use these tips.

[edit] Wireless Security - How-To

There are several steps you can take to secure your network detailed below. Should you? - up to you. Just realise that if you do not then every time you log in to your online bank accounts some guy outside in a car or your neighbour may be scanning your network traffic.

Some people want to offer their network to free loaders - if it doesn't affect their own surfing. If you are going to do this I recommend making the SSID (Network Identifier) a mobile phone number (eg. 07908339298ForAccess) and then using the other security steps below except for the ones related to "stealthing" your SSID. Then just give the password to people near you who call to ask for it. Be careful - you may actually come to know some of your neighbours by name if you do this.

SSID/Stealth

Change the SSID (wireless network name) from the standard one on the router (typically something like "Speedtouch" related to the router make or model) to something else (see below).

Chose a non-standard combination of letters and numbers for the SSID unless you are planning to offer a free ride as described above - the SSID is used in the encryption algorithms and dictionary words can easily be used to disambiguate your encryption and break your network

Do not "broadcast" the SSID (you may have to broadcast it to establish the connection first time with some adapter cards). There is an option in most routers to broadcast or not broadcast the SSID.

Encryption WEP/WPA/WPA-TKIP

There are several generations of security and encryption protocols that have been rolled out with the new wireless networking standards from the IEEE. The quick and easy answer here is to use the strongest form available to you that is compatible with all your hardware. Encryption involves a key - a string of letters and/or numbers - which is used to encrypt and decrypt information being sent between the wireless devices.

Chose a non-standard combination of numbers and letters for your encryption key. The key can be backwards-engineered if someone "sniffs" enough packets from your wireless network, giving them the ability to intercept and read your data - dictionary words are much more easily cracked than random strings.

MAC Address Filtering

Every network device has a MAC address - an individual identifying code - your router, your wireless network cards, your standard ethernet network port, your bluetooth dongle - if it is used for networking it has a MAC address.

Resitrict access to the wireless network to specified network adapters (using "MAC address filtering") - all routers I have seen have the ability to do this. When using MAC filtering on your home network you will need to tell the router to register a new computer the first time it connects. Some routers have a button to do this and others need to be accessed through the web interface to start registration - which usually lasts for a minute or so. If you are opening to the public as suggested above you will need to be on the phone to your neighbour when they want to connect for the first time and register their address. After that the router will let them in.

Finally,

Change your SSID and encryption key every month or two. If someone has cracked your network they will have to crack it again. If you take all the steps recommended towards securing your network they will in all likelihood not bother but just move on down the road to find someone who has not done so.

It is very easy for someone to break your network security and steal your gaming bandwidth or personal data if you don't take the above steps when setting up your wireless network.

[edit] Signal Problems

Depending on the technology you are using your wireless network will have a certain range in which the signal is strong enough to be used. If you try and use a computer at or towards the end of this range you will experience problems such as a slow connection, intermittent failures and random disconnections.

The effectiveness of your equipment can be improved by following a few simple steps to maximise signal strength where you want it.

- Try to locate the wireless router or access point somewhere in the middle of the physical space you want it to serve.

- Try not to locate receiving devices near other electrical equipment that makes a lot of background noise/electromagnetic radiation, such as CRT monitors, Televisions and computers (yes this one is tricky).

- If you have a PCI wireless card installed in the computer and are getting weak signal problems you can buy an antennae on an extension cable that will screw into the back of the card but allow you to move the antennae away from the computer and screen where it will suffer less interference.

- Wireless network equipment will operate on ten or more frequencies within the 2.4Ghz range. there are several other types of consumer device that share this frequency including microwave ovens and cordless telephones. If you are having weak signal problems try switching through all the available frequencies (set in the router or access point web interface) to see if any offer better reception than the others - they usually do.

- Try turning off your cordless phone and see if that is causing the problem. If it is an old one it may need replacing.

- You may be on a conflicting bandwidth with your neighbours wireless router, cordless phone or even badly maintained microwave oven - again switching frequencies will often resolve this.

- If you are trying to connect to your hobby shed or writing retreat at the end of the garden and find you can not get a strong enough signal you can buy a high gain antennae - or just build a parabolic antennae using a usb wireless adapter and some Asian cookware or wire mesh to make the parabolic dish.

Instructions can be found here. (ref?)

[edit] Getting the most from your connection

There is no point paying for 8Mb/s internet and connecting wirelessly to it at 1Mb/s because all you will get is the slowest bit of the network bottlenecking the rest. Check the connection speed your computer is connected at and make sure it at least doubles the speed of your internet. Throughput on wireless is a little over half the "connection" speed. If it's too low move something or do one of the other things recommended above.

Finally ... to get the most out of any broadband on any connection ... run TCPOptimizer to max the useage of your bandwidth .. this alone sees significant (up to 50%) speed increases for almost all users - unless you are using Windows Vista which it will slow down. Note that some wireless adapters fail to function correctly after use of this program. It is always advisable to backup current settings before applying changes.

--CrazyBuddhist-7242 14:28, 21 November 2007 (EST)