Home
Product Directory
Product Installation
Product Activation
Buy

Products > Network+ > Cram Notes
   

Network+(N10-005) Cram Notes

Previous        Next  

3.3 Compare and contrast different wireless standards.

  802.11a 802.11b 802.11g 802.11n

Distance

35m indoors/ 120 m outdoors

32m indoors/140m outdoors

32m indoors/140m outdoors

70m indoors/250 m outdoors

Speed 54 Mbps 11 Mbps 489 Mbps 130-150 Mbps
Frequency 5GHz 2.4GHz 2.4 GHz 2.4 GHz and 5 GHz

   Multiple Input Multiple Output

It uses multiplexing to increase the range and speed of wireless networking. It enables the transmission of multiple data streams traveling on different antennas in the same channel at the same time. A receiver reconstructs the streams, which have multiple antennas as well.

3.4 Categorize WAN technology types and properties.

  • The transmission speed of a T1 circuit (Used mainly in North America) is 1.544Mbps
  • The transmission speed of an E1 circuit (Used mainly in Europe) is 2.048Mbps.
  • The transmission speed of a T3 circuit (Used mainly in North America) is 44.736 mbps
  • OC stands for Optical Carrier and is used to specify the speed of fiber optic networks conforming to the SONET standard.
    Below are the speeds for some common OC levels.
    OC level Speed
    OC-1 = 51.85 Mbps
    OC-3 = 155.52 Mbps
    OC-12 = 622.08 Mbps
    OC-24 = 1.244 Gbps
    OC-48 = 2.488 Gbps
    OC-192 = 9.952 Gbps
  • DSL: DSL uses existing copper telephone lines. DSL technologies typically provide speeds up to 1.544 Mbps.
  • Cable modem: Cable modem uses the same line as cable TV. Possible bandwidth for Internet access reaches up to 27 Mbps.
  • ISDN: ISDN comes in two flavors- BRI and PRI. The most commonly used is BRI, Basic Rate Interface. BRI is composed of two 64-Kbps B (bearer) channels and one 16 Kbps D (delta) channel. ISDN supports both voice and video. ISDN specifies two standard access methods:

1. BRI (Basic Rate Interface): Consists of two B channels (64Kbps) and one D channel (16Kbps).
The B channels can be used for digitized speech transmission or for relatively high-speed data transport.
The D channel carries signaling information (call setup) to control calls on B channels at the UNI (User-Network Interface)

2. PRI (Primary Rate Interface): Consists of 23 B channels and one D channel with a bandwidth of 1.544Mbps. PRI uses a DSU/CSU for a T1 connection. B stands for Bearer Channel.

  • WiMAX is a short name for Worldwide Interoperability of Microwave Access. WiMAX is described in IEEE 802.16 Wireless Metropolitan Area Network (MAN) standard. It is expected that WiMAX compliant systems will provide fixed wireless alternative to conventional DSL and Cable Internet. Typically, a WiMAX system consists of two parts:

1. A WiMAX Base Station: Base station consists of indoor electronics and a WiMAX tower. Typically, a base station can cover up to 10 km radius (Theoretically, a base station can cover up to 50 kilo meter radius or 30 miles, however practical considerations limit it to about 10 km or 6 miles). Any wireless node within the coverage area would be able to access the Internet.

2. A WiMAX Receiver: The receiver and antenna could be a stand-alone box or a PCMCIA card that sits in your laptop or computer. Access to WiMAX base station is similar to accessing a Wireless Access Point in a WiFi network, but the coverage is more.

  • LTE, or long-term evolution, is a type of mobile broadband that rivals WiMAX. Both services are IP-based and use a technology called orthogonal frequency-division multiplexing (OFDM) access. They also use a type of wireless technology that lets people get high-speed Internet across coverage areas that span miles. The standard is maintained as a project of the 3rd  Generation Partnership Project (3GPP), operating under a name trademarked by one of the associations within the partnership, the European Telecommunications Standards Institute (ETSI).
  • The goal of LTE is to increase the capacity and speed of wireless data networks utilizing cutting-edge hardware and DSP techniques that have recently been developed. Its wireless interface is incompatible with 2G and 3G networks, and so it must be operated on separate wireless spectrum.
  • Features of LTE include an all-IP flat network architecture, end-to-end QoS including provisions for low-latency communications, peak download rates nearing 300 mbps and upload rates of 75 mbps, capacity exceeding 200 active users per cell, the ability to manage fast-moving mobiles, and support for multi-cast and broadcast streams.

Previous        Next  

 
FAQ
Contact Us
Disclaimer