Last updated: October 30, 2013
This section is only applicable to the lab application.
This topic includes information on:
Circuit Switched Fallback (CSFB) is one of the solutions to deliver voice service in LTE network. When a UE is camped on the LTE network, it needs to fallback to the CS domain when a voice call is initiated or received. CS fallback from E-UTRAN to CDMA2000 enables the delivery of CS-domain services by reuse of the CDMA2000 infrastructure when the UE is served by E-UTRAN. The CS fallback is only available where E-UTRAN coverage overlaps with CDMA2000 coverage.
The figure below shows the reference architecture for E-UTRAN to CDMA2000 CS fallback Test.
You can use the test set as a CDMA2000 network simulator for CSFB test, by setting up a connection between the test set and an E-UTRAN/EPC system simulator. As shown in the figure above, eNodeB, Serving Gateway (S-GW), PDN Gateway (P-GW), and Mobility Management Entity (MME) are simulated by Keysight PXT. CDMA2000 BTS, Interworking System (IWS), and MSC are simulated by the test set.
The test set processes the CS fallback signalling messages received from S102 tunnel, and provides the appropriate response to S102 tunnel. Therefore, the UE can perform registration to CDMA2000, receive CDMA2000 paging, or send SMS, while it is still in E-UTRAN.The signalling messages between UE and CDMA2000 system are communicated through E-UTRAN air interface and S102 tunnel. The S102 is the reference point between the MME and the CDMA2000 IWS. It provides a tunnel between MME and IWS to relay CDMA2000 1xCS signalling messages.
The figure below shows a typical Physical connection for E-UTRAN to CDMA2000 CS fallback Test.
For detailed guidance on how to use the E6621A PXT, please refer to the E6621A user's guide at
http://cp.literature.keysight.com/litweb/pdf/E6621-90002.pdf
Active Cell
and System Type is
IS-2000
.Note that there are two LAN Ports on the rear panel of the test set (See Rear Panel Connectors ). For E-UTRAN to CDMA2000 CS fallback, LAN 2 PORT is required to exchange signaling message or packet data. LAN 1 PORT is optional, but it is still useful for other LAN operations such as protocol logging, firmware downloads or screen captures.
Before the test, you need to make the following operations:
Note | ||
---|---|---|
Operating Mode | General settings to make 1x CSFB applicable | |
IS-2000 | ||
Protocol Revision | ||
Radio Config | RC3, 4, 5, 6 (F-RC11/R-RC8) | |
Service Option | Voice SO (SO3, SO68, SO70, SO73) SMS SO (SO6, SO14) | |
Cell Band/Channel/SID/NID | Enable UE to camp onto CDMA2000 | |
Set to the IP Address of External EPC | ||
N/A | An action to ensure the External EPC Connection Status is Connected | |
To enable CS Fallback from LTE to CDMA2000 | ||
Timer Based Registration State | Off | |
ATIM Indicator | ||
E-UTRAN Neighbor List record setting | Enable Cell reselection to LTE |
The following steps are required to configure the test set:
Use the scenario file created in Phase 1:
On
.This topic includes information on:
The
E-UTRAN/CDMA2000 Interworking Information
window displays counters to help you access the settings and results for external EPC connection and Circuit Switched Fallback (1xCSFB) configuration. The following information are displayed:
Specifies the external EPC connection status. It indicates whether there is a connection or not between the testset and the Evolved Packet Core (EPC) simulator.
GPIB Command: SYSTem:STATus:COMMunicate:LAN:EPCore:CONNected[:STATe]?
Specifies the IP address of the external EPC that is connected to the current testset.
GPIB Command: SYSTem:STATus:COMMunicate:LAN:EPCore:CONNected:ADDRess?
Specifies whether to enable CS fallback from E-UTRAN to CDMA2000 system. This setting is applicable when:
Active Cell
IS-2000
Connected
GPIB Command: CALL[:CELL]:IRAT:EUTRa:CSFBack:STATe
Specifies whether the testset works in normal CSFB mode or enhanced CSFB mode. The testset only supports normal CSFB mode at present. This setting is applicable when:
Active Cell
IS-2000
Connected
On
Specifies the external EPC simulator's IPv4 address. The test set can connect to the EPC simulator with this address via the LAN connection.
This setting is non-volatile (it persists across partial and full presets and power-cycling the test set).
GPIB Command: SYSTem:COMMunicate:LAN:EPCore:ADDRess
This action establishes a connection between the test set and the EPC simulator specified by Ext EPC IP Addr .
GPIB Command: SYSTem:COMMunicate:LAN:EPCore:CONNect
When an connection is established between the test set and the EPC simulator, this action disconnects the test set from the external EPC simulator.
GPIB Command: SYSTem:COMMunicate:LAN:EPCore:DCONnect
Specifies whether to enable CS fallback from E-UTRAN to CDMA2000 system. This setting is applicable when:
Active Cell
IS-2000
Connected
GPIB Command: CALL[:CELL]:IRAT:EUTRa:CSFBack:STATe
Specifies whether the test set works in normal CSFB mode or enhanced CSFB mode. The test set only supports normal CSFB mode at present. This setting is applicable when:
Active Cell
IS-2000
Connected
On
To access the
E-UTRAN/CDMA2k Interworking Info
from the front panel, press
Call Setup
and then press the left
More
key until you reach the
Call Control 5 of 5
menu, select
E-UTRAN/CDMA2k Interworking Info
(
F5
).