Communications
Computer communications describes a process in whch two or more computers or devices transfer data, instructions,and information
(sending device) - (communications channel)-( receiving device)
User of Computer Communications
user can send and receive wireless messages using wireless messaging services
1.Text messaging
(SMS) allows users to send
and receive short text messages on a phone or other mobile device or computer
2.Picture messaging allows users to send
pictures and sound files
3.Video messaging allows users to send
short video clips
4.Wireless instant
messaging allows wireless users to exchange real-time messages with one or more
other users
Wireless Internet access points allow people to connect wirelessly to the internet from home,work,school,and in many public locations
A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order tp determine the Gps receiver's geographic location
Groupware-helps groups of people work together on projects and share information over a network
-Component of work group computing
-Major feature is a group scheduling
Voice mail-is allows someone to leave a voice message for one or more people
-computer in voice mail system converts an analog voice message into digital form
-a voice mailbox is a storage location on a hard disk int he voice mail system
Many programs provide a means to collaborate, or work online ,with other users connected to a server
Collaboration software includes tools that enables users to share documents via online meeting and communicate with other connected users for example online meeting ,web conferences and document management systems
Web services enable programmers to create applications that communications with other remote computer over the Internal or on an internal business network
A mashup is a web application that combines services from two or more sorces
Networks
A network is a collection of computers and devices connected together via communications devices and transmission media. Advantages of a network include: Facilitating communications, Sharing hardware and software, Transferring funds, Sharing data and information.
A local area network (LAN) is a network that connects computers and devices in a limited geographical area. A wireless LAN (WLAN) is a LAN that uses no physical wires. A metropolitan area network (MAN) connects LANs in a metropolitan area. A wide are network (WAN) is a network that covers a large geographical area.
The design of computers, devices, and media on a network is sometimes called the network architecture. P2P descirbes an Internet network on which users access each other's hard disks and exchange files directly over the Internet. A network topology refers to the layout of the computers and devices in a communications network. An intranet is an internal network that uses Internet technologies. An extranet allows customers or suppliers to access part of its intranet.
Network Communications Standards
Ethernet is a network standard that specifies no computer controls when data can be transmitted.
The token ring standard specifies that computers and devices on the network share or pass a special (token).
TCP/IP is a network standard that defines how messages are routed from one end of a network to another.
Wi-Fi identifies any network based on the 802.16 standard that facilitates wireless communication.
Sometimes referred to as wireless Ethernet.
Bluetooth defines how two Bluetooth devices use short-range radio waves to transmit data.
UWB (ultra-wideband) specifies how two UWB devices use short-range radio waves to communicate at high speeds.
IrDA transmits data wirelessly via infrared (IR) light waves.
RFID uses radio signals to communicate with a tag placed in or attached to an object, animal, or person.
Communications software consists of programs that: Helps users establish a connection to another computer or network. Manage the transmission of data, instructions, and information.
Communications Over the Telephone Network
The public switched telephone network (PSTN) is the worldwide telephone system.
A communicaation device is any type of hardware capable of transmitting data, instructionsm and information between a sending device and a receiving device.
A dial-up modem converts signals between analog and digital.
A digital modem sends and receives data and information to and from a digital line.
A wireless modem uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device.
A network card enables a computer or device to access a network.
Available in a variety of styles.
Wireless network cards often have an antenna.
Communications Devices
A wireless access point is a central communications device that allows computers and devices to transfer data wirelessly among themselves or to a wired network.
A router connects multiple computers or other routers together and transmits data to its correct destination on a network.
Many are protected by a hardware firewall.
A hub or switch connects several devices in a network together.
Home Networks
Home networks provide computers with the following capabilities: Connect to the Internet at the same times, Play multiplayer games, Connect game consoles to the Internet.
Communications Channel
the amount of data that can travel over a communications channel sometimes is called the bandwidth.
Latency is the time it takes a signal to travel from one location to another on a network.
Transmission media carries one or more signals.
Broadband media transmit multiple signals simultaneously.
Wireless Transmission Media
Cellular radio is a form of broadcast radio that is used widely for mobile communications.
Microwaves are radio waves that provide a high-speed signal transmission.
A communications satellite is a space station that receives microwave signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area.
A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order tp determine the Gps receiver's geographic location
Groupware-helps groups of people work together on projects and share information over a network
-Component of work group computing
-Major feature is a group scheduling
Voice mail-is allows someone to leave a voice message for one or more people
-computer in voice mail system converts an analog voice message into digital form
-a voice mailbox is a storage location on a hard disk int he voice mail system
Many programs provide a means to collaborate, or work online ,with other users connected to a server
Collaboration software includes tools that enables users to share documents via online meeting and communicate with other connected users for example online meeting ,web conferences and document management systems
Web services enable programmers to create applications that communications with other remote computer over the Internal or on an internal business network
A mashup is a web application that combines services from two or more sorces
Networks
A network is a collection of computers and devices connected together via communications devices and transmission media. Advantages of a network include: Facilitating communications, Sharing hardware and software, Transferring funds, Sharing data and information.
A local area network (LAN) is a network that connects computers and devices in a limited geographical area. A wireless LAN (WLAN) is a LAN that uses no physical wires. A metropolitan area network (MAN) connects LANs in a metropolitan area. A wide are network (WAN) is a network that covers a large geographical area.
The design of computers, devices, and media on a network is sometimes called the network architecture. P2P descirbes an Internet network on which users access each other's hard disks and exchange files directly over the Internet. A network topology refers to the layout of the computers and devices in a communications network. An intranet is an internal network that uses Internet technologies. An extranet allows customers or suppliers to access part of its intranet.
Network Communications Standards
Ethernet is a network standard that specifies no computer controls when data can be transmitted.
The token ring standard specifies that computers and devices on the network share or pass a special (token).
TCP/IP is a network standard that defines how messages are routed from one end of a network to another.
Wi-Fi identifies any network based on the 802.16 standard that facilitates wireless communication.
Sometimes referred to as wireless Ethernet.
Bluetooth defines how two Bluetooth devices use short-range radio waves to transmit data.
UWB (ultra-wideband) specifies how two UWB devices use short-range radio waves to communicate at high speeds.
IrDA transmits data wirelessly via infrared (IR) light waves.
RFID uses radio signals to communicate with a tag placed in or attached to an object, animal, or person.
Communications software consists of programs that: Helps users establish a connection to another computer or network. Manage the transmission of data, instructions, and information.
Communications Over the Telephone Network
The public switched telephone network (PSTN) is the worldwide telephone system.
A communicaation device is any type of hardware capable of transmitting data, instructionsm and information between a sending device and a receiving device.
A dial-up modem converts signals between analog and digital.
A digital modem sends and receives data and information to and from a digital line.
A wireless modem uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device.
A network card enables a computer or device to access a network.
Available in a variety of styles.
Wireless network cards often have an antenna.
Communications Devices
A wireless access point is a central communications device that allows computers and devices to transfer data wirelessly among themselves or to a wired network.
A router connects multiple computers or other routers together and transmits data to its correct destination on a network.
Many are protected by a hardware firewall.
A hub or switch connects several devices in a network together.
Home Networks
Home networks provide computers with the following capabilities: Connect to the Internet at the same times, Play multiplayer games, Connect game consoles to the Internet.
Communications Channel
the amount of data that can travel over a communications channel sometimes is called the bandwidth.
Latency is the time it takes a signal to travel from one location to another on a network.
Transmission media carries one or more signals.
Broadband media transmit multiple signals simultaneously.
Wireless Transmission Media
Cellular radio is a form of broadcast radio that is used widely for mobile communications.
Microwaves are radio waves that provide a high-speed signal transmission.
A communications satellite is a space station that receives microwave signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area.
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