Wireless Networks
By Lisa Christian.
There are a variety of wireless network concepts and technologies to consider. Some of these areas include:
Mobiles past
Commercial wireless networks
Use of mobiles
Locations of mobile reach – global and in Australia. Including history, reach and growth.
GSM, CDMA and PDC are mobile network types.
TDMA based is a current networking technology.
Different types of mobile networks are being used currently.
AT&T wireless has had recent progressions.
"Wireless networks are computer networks that use wireless data connections between network nodes12. They allow homes, telecommunications networks, and business installations to avoid the costly process of introducing cables into a building, or as a connection between various equipment locations.” (Wikipedia, 2024).
Brief History.
In the 1950s, the bell telephone in the US introduced the radio telephone service.
1971, FCC in the US, allocated a band for radio telephony.
1982, Amps system specifications developed for North America.
Also, in this year, GSM was created. This is for current mobile standards and technologies. It is the same standard that is used today!
“The first professional wireless network was developed under the brand ALOHAnet in 1969 at the University of Hawaii and became operational in June 1971. The first commercial wireless network was the WaveLAN product family, developed by NCR in 1986.
(Wikipedia, 2024).
Cellular Fundamentals.
Can be divided into RAN (radio access network) and core networks.
Concepts of cellulars, include: frequency, reuse, multiple access techniques, speech coding and authentication.
Use of RF Equipment.
Core Network.
Mobile switching centres (msce), home location register (hlr) and visitor relocation register (vlr).
SMSC is a 3 way call technology, with a gsm map and switching functionality, accesses services for circuit switch data.
Example: call to the operator, the operator puts you through. Then more recently you dial the extension or the voice chooses the line or service.
Internet-working function (IWF) circuit switch data, in wireless networks.
Multiple Access.
It can be divided into subportions:
FDMA – Frequency division multiple access.
TDMA – Time division multiple access.
CDMA – Code division multiple access.
Frequency reuse, means frequency is recycled.
Speech and Channel Coding
Digital transmission systems.
Speech coding for wireless networks.
Channel coding aims to improve quality when there is interference.
Mobility.
Supports up to 120kmph roamng.
So if a pedestrian moves superfast, the mobile transmission is able, to move with it.
“Terrestrial microwave – Terrestrial microwave communication uses Earth-based transmitters and receivers resembling satellite dishes. Terrestrial microwaves are in the low gigahertz range, which limits all communications to line-of-sight. Relay stations are spaced approximately 48 km (30 mi) apart.
Communications satellites – Satellites communicate via microwave radio waves, which are not deflected by the Earth's atmosphere. The satellites are stationed in space, typically in geosynchronous orbit 35,400 km (22,000 mi) above the equator. These Earth-orbiting systems are capable of receiving and relaying voice, data, and TV signals.
Cellular and PCS systems use several radio communications technologies. The systems divide the region covered into multiple geographic areas. Each area has a low-power transmitter or radio relay antenna device to relay calls from one area to the next area.
Radio and spread spectrum technologies – Wireless local area networks use a high-frequency radio technology similar to digital cellular and a low-frequency radio technology. Wireless LANs use spread spectrum technology to enable communication between multiple devices in a limited area. IEEE 802.11 defines a common flavor of open-standards wireless radio-wave technology known as Wi-Fi.
Free-space optical communication uses visible or invisible light for communications. In most cases, line-of-sight propagation is used, which limits the physical positioning of communicating devices.”
Wikipedia, 2024.
Types of Wireless Networks.
LAN – Local area network.
WLAN – Wireless local area network.
WAN – Wide area network.
MAN – Metropolitan area network.
SAN – Storage area network. (Also, system area network or small area network.)
CAN – Campus area network.
PAN – Personal area network.
DAN -Desk area network.
“The telecommunications network at the physical layer also consists of many interconnected wireline network elements (NEs). These NEs can be stand-alone systems or products that are either supplied by a single manufacturer or are assembled by the service provider (user) or system integrator with parts from several different manufacturers.
Wireless NEs are the products and devices used by a wireless carrier to provide support for the backhaul network as well as a mobile switching center (MSC).
Reliable wireless service depends on the network elements at the physical layer to be protected against all operational environments and applications (see GR-3171, Generic Requirements for Network Elements Used in Wireless Networks – Physical Layer Criteria).[19]
What are especially important are the NEs that are located on the cell tower to the base station (BS) cabinet. The attachment hardware and the positioning of the antenna and associated closures and cables are required to have adequate strength, robustness, corrosion resistance, and resistance against wind, storms, icing, and other weather conditions. Requirements for individual components, such as hardware, cables, connectors, and closures, shall take into consideration the structure to which they are attached.”(Wikipedia, 2024.)
LAN.
A lan, connects network devices over short distances.
TCP/IP is a lan, but not always a single subnet.
Lan uses token ring topology or ethernet a lot.
WAN.
Wan is a large network spanning large distances, eg. The internet with global reach.
A wan is a geographically – dispersed collection of lans.
A router connects lans to a wan.
ATM, frame relay technologies. X.25 for longer distances.
ISP connects the wan to the lan, by providing an IP address to the router.
STORAGE AREA NETWORK.
Connects servers to data.
Also known as cluster area network.
Ethernet.
ISP provides a dsl or cable modem.
A router makes the internet plug and play, to set up a home network.
Uses twisted pair cable or fibre optics.
Home wiring.
WLAN.
Wireless lan, IEEE 802.11 standard.
Operates at 2.4gHz – 5g Hz.
The wifi alliance has tested products for interoperability.
WPAN
Wireless Pan, 802.15 IEEE standard.
Eg. bluetooth!
LR-WPAN
Low right, wireless pan.
Zigbee for industrial equipment to communicate to each other when nearby each other.
Power lines communication.
Delivering IPTV.
Essential for home networking.
General purpose.
A network attached storage (NAS) ie phone, tablet, laptop, computer, etc. for home networking.
Also for home audio.
Home automation.
Smoke alarms, garage doors, lighting.
Wireless on/off switches.
HVAC nest thermostats.
Embedded devices.
Often configured through a web browser, to the router.
Windows PCs.
For home networking.
Where passwords are not required.
Wireless signal loss.
May not be strong enough to reach the whole house.
A router can extend the signal.
References.
2024, Wikipedia. 'Wireless network – Wikipedia'.
Accessed from: Wireless network – Wikipedia on: 14/2/24.
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