Installation Manual

Chapter 1 - System Description System Overview
BreezeMAX Extreme 18 System Manual
capabilities. It also encompasses the bearer plane methods (e.g. tunneling) to
transfer user data between the ASN and CSN.
 Reference point R4 consists of the set of control and bearer plane protocols
originating/terminating in various functional entities of an ASN that
coordinate MS mobility between ASNs and ASN-GWs. R4 is the only
interoperable reference point between similar or heterogeneous ASNs. R4 is
supported only when Centralized ASN GW is deployed.
 Reference point R5 consists of the set of control plane and bearer plane
protocols for internetworking between the CSN operated by the home NSP and
that operated by a visited NSP. R5 is supported only when Centralized ASN
GW is deployed.
 Reference point R6 consists of the set of control and bearer plane protocols
for communication between the BS and ASN-GW. The bearer plane consists of
an intra-ASN data path between the BS and ASN gateway. The control plane
includes protocols for data path establishment, modification and release
control in accordance with the MS mobility events. R6 is supported only when
Centralized ASN GW is deployed.
 Reference point R8 consists of the set of control plane message flows and
optional bearer plane data flows between the base stations to ensure a fast
and seamless handover. The bearer plane consists of protocols that allow data
transfer between base stations involved in the handover of a certain MS. R8 is
supported only when Centralized ASN GW is deployed.
NOTE
All reference points are logical and do not necessarily imply a physical or even direct connection.
For instance, the R4 reference point between ASN-GWs might be implemented across the NAP
internal transport IP network, in which case R4 traffic might traverse several routers from the source
to the destination ASN-GW.