Dauninam

SEMIS

SONET - Synchronous Optical Network

SDH - Synchronous Digital Hierarchy

STS - Synchronous Transport Signal-1

STE - Synchronous Payload Envelope

POTS - Plain Old Telephone Service

PBX - Private Branch Exchange

ISDN bit pipe supports multiple channel interleave

A. 4 KHz analog telephone channel

B. 64 Kbps digital PCM channel for voice or data

C. 8 or 16 Kbps digital channel

D. 16 Kbps digital channel for out-of-band signaling

E. 64 Kbps digital channel for internal ISDN signaling

F. 384, 1536, or 1920 Kbps digital channel

CCITT Three combination have been standardized

1. Basic rate: 2B + 1D

2. Primary rate: 23B + 1D (US & Japan) – 64Kbps or 30B+1D (Europe) – 2.048Mbps

3. Hybrid: 1A + 1C

AMPS (Advanced Mobile Phone System)

-created by Alexander Graham Bell

-1st install in US in 1982 by Bell Labs

-uses 832 Full Duplex Channel

832 Full Duplex Channel divided into 4 categories:

1. Control (Base to mobile) to manage the system.

2. Paging (Base to mobile) to alert the mobile to call from them.

3. Access (By directional) for call setup and channel assignment.

4. Data (By directional) for voice, fax, data.

MSC – Mobile Switching Center

MTSO – Mobile Telephone Switching Office

GSM – Global System for Mobile Communication

PCS – Personal Communication Services

PCN – Personal Communication Network

VSAT – Very Small Aperture Terminals

The data link layer can be design to offer various services. The actual services covered can vary from system to system. Three reasonable possibilities that are commonly provided by data link layer.

1. Unacknowledged Connection Service

2. Acknowledged Connectionless Service

3. Acknowledged Connection-Oriented Service