BellSouth E911 - Manual (Page 93)

CG-EWCG-001 Wireless E911 Guide
Issue 3, January 6, 2004 BellSouth Wireless E9–1–1/SS7 Interconnection
Guide
Wireless E9-1-1 Solution (WLS911), a Hybrid architecture functional in both Phase 1 and Phase 2
environments. WSPs should see their BellSouth account team for details on how the WLS911 Solution
may be of value in their overall architecture plans.
A.7 Interface Protocol for Wireless Call Setup when using SS7/ISUP signaling.
A WSP choosing to interconnect with SS7 trunks using ISUP signaling in support of delivery of
Wireless E9-1-1 calls shall comply with one of the following three signaling options available in the
BellSouth E9-1-1 Network. On the BellSouth NDET switches the options are known as "WRLS_STD"
or "WRLS_CLD" or "E911_STD". Any one of these three can be supported on the BellSouth NDET
switches on a per incoming trunk group basis. (They would of course be known by other nomenclature
designations on various Wireless switches.)
NOTE: The WRLS_STD signaling option is used when the pANI is located in the Generic Digits (GDP)
Parameter. Calling Party Number is used as the callback number. Charge Number is ignored by the NDET.
This is the industry standard for wireless calls on the NDET.
The WRLS_CLD signaling option is used when the pANI is located in the Called Party Number parameter,
instead of the digits 9-1-1. Calling Party Number is used as the callback number. Charge Number is
ignored by the NDET. Generic Digits (GDP) Parameter IS NOT ALLOWED!
Depending on which signaling option is chosen, the WSP will send an Initial Address Message (IAM)
containing the following parameters when sending a wireless E9-1-1 call to a BellSouth E9-1-1 tandem:
• Calling Party Number Parameter
• Called Party Number Parameter
• Generic Digits (GDP) Parameter (NOT allowed if the WSP uses WRLS_CLD)
• Charge Number Parameter
NOTE: Although Charge Number Parameter is allowed as an optional parameter, it is ignored
by the NDET when using either of the WRLS_xxx signaling options.
• Calling Party Category Parameter
• Originating Line Information Parameter Calling Party Number Parameter
A.7.1 Calling Party Number
The Calling Party Number parameter value is variable depending upon which trunk group signaling option
is being used. If the intention is to achieve Wireline Compatibility Mode (using E911_STD), the Calling
Party Number parameter shall contain the pANI that will be used for Selective Routing, and will be sent to
the PSAP to retrieve additional call data via the ALI database path. Otherwise, in either of the WRLS_xxx
signaling options the Calling Party Number parameter shall contain the caller’s CBN (or a number being
used as a substitute when the CBN is unknown).
The wireless carrier shall specify the contents of the Calling Party Number (i.e., the CBN or a pANI) at
the time the trunk group is ordered (via their BellSouth account team using form RF-1004-WS). Once a
trunk group is provisioned, the wireless carrier shall adhere to their choice (i.e., a trunk cannot signal the
CBN for one call and a pANI for another call).
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