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TRAFFIC MANAGEMENT AND NETWORK DESIGN
AB-ACCESS™ TRAFFIC MANAGEMENT
The AB-Access™
innovative traffic management ensures maximum efficiency of data
transmission, maximizing bandwidth use and hence revenue. Cell sites and
subscriber units employ sophisticated media access control mechanisms, and
innovative traffic management is present at all levels of the network,
from the network manager to individual data transmissions from
subscribers. The patented Axxcelera Broadband Packet-on-Demand technology
and superior MAC (Media Access Control) ensure the exceptional bandwidth
management efficiency which AB-Access™ provides, with up to ten times the
Internet data throughput of other systems.
High Granularity Bandwidth Allocation
Beyond
bandwidth-on-demand, AB-Access allocates bandwidth to users at the
granularity of a single cell, avoiding wasted bandwidth and greatly
increasing the effective use of the available bandwidth. No aspect
of bandwidth is committed, allowing dynamic allocation of resources to
serve only users with data to transmit. A conventional approach of
assigning larger 'chunks' of bandwidth is wasteful, as a user often
doesn't use the assigned bandwidth for 100% of the time. The granularity
of AB-Access™ means that available bandwidth is used in the most efficient
way.
For more information see our Packet-On-Demand description.
Support for Traffic Asymmetry
AB-Access™ supports the highly
asymmetric traffic patterns which are typical of Internet-type
applications, where servers are often located at both sides of the
network. The time division duplexing approach means that each data channel
is used for both upstream and downstream traffic, dynamically altering
direction according to traffic load. This greatly increases the efficiency
of spectrum use, with the spectrum dynamically altering from upstream to
downstream in less than a millisecond, as compared to traditional
frequency duplexed systems, which allocate fixed partitions of spectrum to
upstream and downstream traffic, resulting in unused spectrum.
OPTIMIZING DATA THROUGHPUT
Robust Error Correction
Over the air errors are corrected by
retransmitting cells that are in error. This correction on a cell by cell
basis minimizes the time taken and avoids wasting bandwidth. AB-Access is
highly resistant to both burst errors and interference.
NETWORK DEPLOYMENT
AB-Access networks are designed for rapid and easy deployment, and constructed from a number of cell sites deployed in a conventional cellular pattern. The network can be deployed according to subscriber locations and marketing strategy, from a number of small island sites to complete coverage of a chosen geographical area. The wireless nature of the network means that it can be deployed in days or weeks as opposed to the months or even years a wired network requires. Initial deployment can be limited to a few cell sites and the network incrementally rolled out as subscriber numbers grow, with on-going costs incurred only when service subscribers sign up. Cell sites and subscriber units are integrated units, reducing equipment costs and installation time. The network is managed from a single central point, for economic operation of the network.
BACKHAUL
Choice of backhaul from cell sites is an important economic factor. AB-Access can use a variety of different mechanisms depending upon subscriber density and network size.
Wired Backhaul
Multiple types of wired backhaul are
supported, including multiple T1s, OC3, or DS3. The wired backhaul
facility is connected to the ATM switch using the appropriate interface
card.
Wireless Backhaul
A variety of wireless backhaul mechanisms
can be used:
- Via an existing access point, where traffic is consolidated into another cell's backhaul, useful in low density areas
- Via the AB-Extender point-to-point product.
- Via a commercially available point-to-point link using another available licensed or unlicensed frequency
SECURITY
Access Network Protection
The security provisions of
AB-Access protect traffic from eavesdropping and theft of service.
ISP Network Protection
To further increase security,
additional protection mechanisms can be used:
- IP Protocols - secure IP protocols can be run over the top of the built-in AB-Access protocols
- PPP -an extra measure of service protection can be accomplished through the authentication and authorization of PPP connections
- ATM-level encryption - standard ATM encryption equipment can be used in conjunction with AB-Access
