20-11-2012, 02:00 PM
OPTICAL ARCHITECTURES FORMOBILE BACK- AND FRONTHAULING
OPTICAL ARCHITECTURES.ppt (Size: 1.78 MB / Downloads: 62)
Choice of transmission technology : optical only
Metrics
technical metrics :
bandwidth (scaleability, user statistics), latency, jitter
environmental factors : temperature, humidity, mechanical
location factors : availability of local powering, footprint, accesseability
economic metrics :
infrastructure : ownership, availability of dark fibers, digging cost, leasing cost, opportunity for sharing
location factors : power supply and power consumption, rights of way
Centralized processing : variants and benefits
BBU clustering : move BBU hardware from BTS into common central space
simplified hardware at antenna sites (footprint, electrical power) and in BBU (indoor specs)
„zero latency“ links between BBUs allow for implementing CoMP and ICIC algorithms
BBU pooling : share hardware elements between multiple colocated BBUs
additional benefit : ease of load-sharing between clusters
Either variant requires CPRI links to remote antenna sites
transmission bandwidths easily reach levels that render TDM-PON unattractive
small split factors (1:2 or 1:4)
constant bitrate, i.e. no statistical multiplex gain
strict latency limits (<<1 msec) require zero framing/buffering etc. delays
most viable solutions employ ptp-links via
fiber, if available …
wavelength : ptp-WDM overlay on TDM-PON or „pure“ WDM-PON