Optical Access Networks:
i. The classification of optical access network is dependent on the type of their distribution network that means whether it is broadcast or switched.
ii. Optical access networks could be active or passive. An example of an Active Optical Network (AON) is metro Ethernet or carrier Ethernet.
iii. The other category is Passive Optical Networks (PON). PON works by delivering an end to end fiber access to the building or home. Though PON can be used for FTTC/N applications, most PON applications are based on FTTH/B architecture.
iv. TDM PON is the current choice because of its low cost. Out of the available TDM PON technologies, GPON has much better multi service capabilities and carrier grade management capabilities.
v. Two common wireless access networks are as follows : (i) Multichannel Multipoint Distribution Services (MMDS) (ii) Local Multipoint Distribution Services (LMDS)
vi. MMDS provides a bandwidth of 2 to 3 GHz and it can provide total 33 channels of 6 MHz each. LMDS provides a bandwidth of 1.3 GHz and it is more suitable of short range distances, typically 3 km to 5 km.
From the architecture diagram, the optical access network comprises the following scenarios:
1. FTTB scenario:
As an access scenario for business users, Fiber to The Business (FTTB) scenario falls into single business unit (SBU) and Business Multi-tenant unit (MTU) in terms of capacity. Of them SBU provides a comparatively small number of ports.
2. FTTC & FTTCab scenario:
As an access to the curb or the cabinet over fiber, Fiber to The Curb& Fiber to The Cabinet (FTTC & FTTCab) scenario is for the Multi-dwelling unit (MDU), providing a comparatively larger number of ports.
3. FTTH scenario:
As an access to the home over fiber, Fiber to The Home (FTTH) scenario is mainly for the single family unit (SFU), providing a comparatively small number of ports.