Week 2 Flashcards
What are most communication systems compromised of?
Transmitter
Receiver
Multiple access allows what?
Allows many users to share the communications channel without interfering with one another.
Fixed Assignment Access?
Used for a voice oriented network.
Employed for allocating the traffic channels.
Fixed Assignment Access Traffic Channels?
Frequency Division Multiple Access (FDMA)
Time Division Multiple Access (TDMA)
Spread Spectrum Multiple Access (SSMA)
Traffic?
Traffic is exchanged in both direction for a considerable length of time.
A signaling?
Control Channel exchanges short messages between the calling components to:
Set up the call
Terminate the call
Where is Random Access Method used?
used for data oriented network (packet switched)
Designed for bursts of data
Does not have a separate signaling channel
FDMA?
Frequency Division Multiple Access
What does FDMA do?
All users transmit at once but each user is assigned to its own channel around its carrier frequency
1G networks like AMPS
TDMA?
Time Division Multiple Access
What does TDMA do?
All users share same frequency band but each is user is assigned a unique time slot.
2G Cellular networks, GSM
SSMA?
Spread Spectrum Multiple Access
What does SSMA do?
SSMa employs signals that have a bandwidth which is several orders of magnitude greater than the minimum required bandwidth
PN?
Pseudo Noice
What does PN do?
Pseudo Noice sequence converts a narrowband signal to wideband noise like signal
