OCAM1 Flashcards
Define Optical Communications
Transmission of information by using light over a given distance
Properties of OC (4)
1) Light path is defined by a transmission medium
2) Light is propagated (travel) down the medium by a light source
3) Light is collected and interpreted by a receiver
4) The light signal must account for the properties of light
Applications of OC (5)
1) OC transport networks
2) Cloud computing
3) Carrier ethernet support
4) Data centres
5) Medical centres
What are the key OC technology development for OC Transport Networks? (4)
1) Optical Transmitters
2) Transmission mediums
3) High sensitivity, low noise photo detectors
4) Advanced modulation schemes
Key properties of optical transmitters
1) Continuous-wave lasers are needed for their steady stream
2) Room temperature lasers allow lasers to work at RT and removes need for heat dissipating equipment
What is the transmission medium we use in OC?
Low loss optical fiber
What do photo detectors do?
They collect (receive) light and covert it to an electrical current
What is the purpose of advanced modulation schemes?
They allow for more data to be imposed on the transmission medium
What the advantages of using OC? (5)
1) Greater distances supported
2) Higher service capacity
3) Greater service flexibility
4) Lower cost
5) Increased security
How does OC support greater distances? (2)
1) Low loss optical fibre as the carrier signal
2) Ability to support optical amplification
How does OC support greater capacity? (2)
1) Higher bit rate support
2) Multiple optical signal support when using Wave Division Multiplexing (WDM)
How does OC achieve service flexibility?
By supporting:
1) Sub-lambda electrical client multiplexing using an optical transport protocol
2) Lambda-based services with the use of WDM channels
Why is OC cheaper to use than copper based technologies?
1) A single infrastructure can support all client traffic types
2) Ability to reduce and/or eliminate to need to regenerate
3) Optical amplification allows for distance extension
Types of OC Transport Networks
1) Provider - provider
2) Provider - enterprise
3) Enterprise - enterprise
Define OC Provider
An OC transport network operator that carries data traffic for the purpose of revenue generation or to support operational goals. E.g. Multi-service Operator (MSO), Internet Content Provider (ICP), the government
Define an OC Enterprise
A business entity that does not derive its main revenue stream from carrying another operational entity’s traffic over an OC network. The network is used to support business goals of the lone organisation. E.g. Health Care Network; Utility company
Characteristics of OC Transport Network
1) Higher bandwidth
2) Higher reliability
3) Standardised manageability across operational entities
4) Photonic networks that span data centres; clouds; Metro area networks (MANSs); Wide Area Networks (WANs) and long haul distances (including submarine)
5) Transport voice, video and data within and across geographical locations
Deployment types of OC Transport Networks
1) Metro Area Network (MAN)
2) Long haul terrestrial
3) Submarine
What is a Metro Area Network?
1) Medium distance OC network that connects business and sites in a geographical location like a city
2) Used to collect traffic access to common points for service connectivity
What is a long haul terrestrial network?
The core of OC network that connects different geographical locations, while provide aggregation for MANs. There are 3 types:
1) Long haul (600-1000km)
2) Extended long haul ( 1000-2000km)
3) Ultra long haul (>2000km)
What is a submarine network?
An ultra long haul WAN network that connects different geographical locations that are separated by large bodies of water. Can be used where there are sea depths of up to 8000m with spans reaching thousands of KMs
Protocols used in OC Networks
1) Synchronous Optical Network (SONET)
2) Synchronous Digital Hierarchy (SDH)
3) Optical Transport Network (OTN)
