Specifications

Circuit Switched Data Networking
August 08, 2000 7-1
Chapter 7
Circuit Switched Data Networking
Circuit Data Networking is non-voice communications that utilize other provider
networks. The other networks may be either land-based (PSTN) or wireless
(PLMN). This world-wide interconnected data network provides Fax, modem,
Intranet, Virtual Private Network, Extranet and Internet access. To use Circuit Data
Networking, the iDEN system must be configured for interface to the worldwide
network. This chapter will describe the fundamentals of Circuit Switched
Networking.
General Circuit Switched Networking
To support the logical global dial-up data networking, the iDEN system uses the
interconnect calling infrastructure and general operation to identify and locate the
MS in the iDEN network.
Non-Circuit Switch Network Service
Because Circuit Switched Networking uses equipment outside the iDEN system, this
type of service may be restricted to users on a per-MS basis. This is controlled by
service provisioning.
General
Circuit Switched Networking uses the Interconnect calling functions and
infrastructure with the exception of the Interworking Function (IWF) and the Short
Message Service (SMS) of the MSC. An MS may travel freely throughout an iDEN
system and teamed roaming partners. If Circuit Switched networking is supported
and provisioned, within a extended network, a MS can originate or receive Circuit
Switched Data calls. The systems track the MS's location and services as well as
route the data appropriately.
The major system elements involved in Circuit Switched Networking are shown in
Figure 7-1. The MS sends and receives data directly or to a computing device. The
EBTS converts the radio link to the land network link and determines the call is a
circuit switched interconnect calls. The BSC controls the signaling, and routing of
data packets between the MSC and the EBTS. The MSC determines service
availability and location information with the HLR and VLR. The MSC also controls
and routes the data to and from other provider networks. The IWF is a modem/FAX
bank for PCM compatible data transfers.
Figure 7-1 iDEN Circuit Switched Networking Elements
HLR VLR
Mobile Station
(MS)
RF
DAC
(span
connections)
iSC
ACG
iMU
BSC
(routing and
conversion)
XCDR
MSC
(services &
PSTN routing)
EBTS
(radio link)
T. N .
French
T. N. French
IWF SMS
Fax/Modem
Bank
External,
online
messaging