About Handoff Tests

With a handoff test, you can test the SUT's ability to process handoffs from one device to another. By running the test at various capacity levels and handoff rates, you can determine a SUT's stability under a particular processing load. Data traffic can be added to the test to verify the SUT's ability to maintain data sessions during handoffs.

There are two handoff modes as described in the table below. The handoff test begins by establishing sessions at the session connect rate. You have the option to begin the handoffs as each session is started, or to wait until all sessions have been established before beginning to handoff the sessions. In both cases, the test waits for the defined delay time before executing the first handoff.

When Session Started	Landslide activates the handoff for a UE as soon as the UE attaches to the network and the mobility delay timer expires. Since the handoff is performed when the session starts, the actual mobility rate, or handoff per second, is the session connect rate.
When all sessions started	Landslide waits for ALL the UEs to attach before attempting the first handoff for the first UE. In this mode, the user can define the Handoff Rate (handoff per second) and the distribution settings (fixed, uniform, normal, Poisson).

Both modes support the option to perform a single handoff per UE or continuous handoffs. When continuous handoff is supported and selected, for each UE, the test waits for the Mobility Delay Time to expire. Landslide then performs the handoff and triggers the Mobility Delay Time again before performing the next handoff and so on.

The test continues in this manner through the duration of the test session or until the test is stopped manually or with Automation Control.

Inter-technology Handoff

Inter-technology handoff is also referred to as vertical handoff. A multi-homed MN communicates with one interface at any time. Each interface can support different access technology. Inter-technology handover occurs when MN moves out of coverage of one technology and moves into the coverage area of another technology which will result in switching of the communicating interface on MN.

In LTE testing, Inter-Technology Mobility supports mobility between LTE and non-3GPP technologies and allows you to configure the test to perform inter-RAT handoff scenarios. The handoff protocols supported are: UMTS IuIP, GPRS and eHRPD. You may specify an Initial Network for the test as LTE or Target and the handoff type as Handover or TAU/RAU. As in all mobility test scenarios, handoffs may be configured as continuous or as a single handoff. In addition, data is supported for all handoff scenarios. The following lists the handoff protocol with a brief description:

Handoff Protocol	Landslide Emulates	SUTS
UMTS IuIP	UE, eNodeB and RNC In addition, UMTS IuIP configuration supports the Gn and S3 interfaces. If either the Gn or S3 interface is selected, the Landslide emulates the SGSN.	SGSN MME, SGW and PGW (when SGSN is emulated)
GPRS:	UE, eNodeB and BSS In addition, GPRS configuration supports the Gn and S3 interfaces. If either the Gn or S3 interface is selected, the Landslide emulates the SGSN.	SGSN MME, SGW and PGW (when SGSN is emulated)
eHRPD	UE, eNodeB, ePCF and HSGW	MME, SGW and PGW (supports both Optimized and Non-optimized handoffs)

NOTE: In MME Nodal Inter-Technology testing, when S3 Interface to MME or Gn Interface to MME is used, the test simulates the UE/eNodeB/RNC and SGSN otherwise the test simulates the UE/eNodeB and RNC.

NOTE: SGW Nodal Inter-Tech mobility testing requires your system to be licensed for at least one of the technologies: UMTS, GPRS, or eHRPD.

MME/SGW Nodal Testing

In an Inter-MME handover (Using the S1/S11 Interface (without changing SGW)), two MMEs are involved in the handover, the source MME (S-MME) and target MME (T-MME). The S-MME controls the S-eNodeB and the T-MME controls the T-eNodeB; both MMEs are connected to the same SGW. This handover is triggered when the UE moves from one MME area to another MME area.

Inter-MME test activity you to configure the test to perform handoffs between MMEs. The only handoff type supported for this test is S1. Landslide emulates the UE and both eNodeBs. The MMEs, SGWs and PGW are the SUTs.

NOTE: Inter-MME supports SGW Relocation and you may configure handoff as continuous or as a single handoff, as in all mobility test scenarios.

Intra MME (E-UTRAN) Handover is used to hand over a UE from a source eNodeB to a target eNodeB using S1/S11 interface when the MME is unchanged. The Serving GW is also unchanged. IP connectivity exists between the Serving GW and the source eNodeB, as well as between the Serving GW and the target eNodeB.

Intra-MME test activity allows you to configure the test to perform handoffs between eNodeBs with the MME remaining the same. The only handoff type supported for this test is X2. Landslide emulates the UE and both eNodeBs. The MME, SGWs and PGW are the SUTs.

NOTE: Inter-MME supports SGW Relocation and you may configure handoff as continuous or as a single handoff, as in all mobility test scenarios.

HSGW Nodal Testing

In an Inter-HSGW handoff, a new bearer plane interface is used to tunnel user data between the S-HSGW and the T-HSGW. The tunnel is established after necessary context information is exchanged between the S-HSGW and the T-HSGW via the control plane interface. Then the A10/A11 (ePCF and HSGW, PPP/Open RP) interface is used to tunnel data to/from the Target eAN/PCF (T-eAN/PCF) and the T-HSGW.

For Inter-HSGW handoff testing in AAA Server Nodal test case with S6a/STa Intrfaces, two HSGWs are configured, Source (S-HSGW) and Target (T-HSGW). After eHRPD attach is performed with S-HSGW, the handoff timer is triggered, and T-HSGW starts authentication procedure with AAA through STa interface. Then, the S-HSGW waits for ASR message from AAA, and sends a response. Then HSGW sends STR message to AAA to terminate the STa session and sets the Termination Cause DIAMETER_USER_MOVED.

HNB GW Nodal Testing

In an Intra-HNB GW Mobility handoff, - Handover is used to hand over a UE from a source HNB to a target HNB GW using Iuh/Target Iuh.

In an Inter Macro-HNB Mobility handoff - Support for Inbound mobility from RNC to HNB and outbound from HNB to RNC. (per 3GPP TS 25.467 (release 9)).

AAA Testing

The Inter-PDSN test is available in the AAA Server Nodal test case. It tests the AAA server's ability to process handoffs between two NAS emulators.

A handoff in terms of AAA testing consists of starting a new MN accounting session associated with the handoff NAS, and then stopping the MN's original accounting session.

Reauthentication

Reauthentication on handoff indicates that a MN reauthenticates through the AAA after handoff.

For CSN Nodal test case, enabling Reauthentication on handoff option indicates that MN reauthenticates through the AAA as part of the handoff. When this option is not enabled, a handoff process is performed without any additional AAA requests.

NOTE: During CSN Nodal testing, you can test either reauthentication or mobility handoff at a time, but not both at the same time.

If you select Reauthentication on Handoff, reauthentication is performed only before the handoff occurs. After reauthentication is performed, mobility handoff does not occur and the mobile node is rejected by HA with failed authentication.

If mobility handoff is performed first, reauthentication does not occur.

AMF Nodal - 5G Testing

Intra AMF Mobility Handover is used to hand over a UE from a source gNodeB to a target gNodeB using N1 (NAS-5G) interface when the AMF is unchanged.

Intra-AMF Mobility test activity allows you to configure the test to perform handoffs between gNodeBs with the AMF remaining the same. The only handoff type supported for this test is Xn. Landslide emulates the UE and both gNodeBs. The AMF is the SUT.

In a AMF Nodal Intra-AMF Mobility supports Xn handover, you define the N1 interface with the NAS-5G-Sm, NAS-5G-MM tabs, and Target gNodeB User Node, Target gNodeB Control Node, (User and Control) Nodes.

In a AMF Nodal Inter-AMF Mobility supports N2 handover, you define the N2 interface with the NGAP, NAS-5G-Sm, NAS-5G-MM tabs, and Target gNodeB User Node, Target gNodeB Control Node, (User and Control) Nodes. Adds support for AMF to AMF N2 Mobility scenarios (TAU and Handover) in AMF Nodal.

In a AMF Nodal Dual Connectivity supports RAN Initiated QoS Flow Mobility , per 3GPP 23.502 , 38.413, 29.502. You define the N1 interface with the NAS-5G-Sm, NAS-5G-MM tabs, and gNB User Node, Secondary gNB User Node, gNodeB Control Node, (User and Control) Nodes.

CDMA2000 Testing

The Inter-PDSN test is available in the End-to-End Mobile IP and HA Nodal test cases. It tests the SUT's ability to process handoffs between PDSN-FAs.

The Intra-PDSN test is available in the End-to-End Mobile IP, FA Nodal, Simple IP, and Simple IP VPN test cases. It tests a PDSN-FA's ability to process handoffs between emulated PCFs.

GPRS Testing

The Inter-SGSN test can be used in the GGSN Nodal test case to test a GGSN's ability to process handoffs between emulated SGSNs.

IP Data Testing

Mobile Node Mobility test is available in the PDG Micro-Mobility test case. It tests a PDG's ability to maintain IPSec tunnels with MNs as they move between wireless access nodes and receive new local IP addresses.

Mobile IP Testing

The Inter-FA test is available in the IPv4 HA Nodal test case. It tests an HA's ability to process handoffs between FAs.

In the IPv4 HA Nodal, and IPv6 HA Nodal test cases, Mobile Node Mobility tests an HA's ability to process MN movements between foreign networks. In the CDMA/WiFi Convergence test case, Mobile Node Mobility tests a PDIF's ability to maintain an IPSec tunnel to the MN as it moves between co-located care-of addresses.

The Returning Home test is available in the IPv6 HA Nodal test case. It tests an HA's ability to process MN movements between a foreign link and the home link.

The Inter-Technology Mobility test is available in the CDMA/WiFi Convergence test case. It tests a PDIF's ability to process handoffs between WiFi and CDMA2000 networks.

SMF Testing

Inter Technology Mobility in SMF Nodal Test Case supports the Inter-Tech 5gs/Eps(4g) Handover procedure described in 4.11.1.2.1 and 4.11.1.2.21 in TS23.502. In the procedure depicted in 4.11.1.2 in TS23.502, SMF Nodal simulates UE/NG-RAN(user-plane only)/AMF/SGW against SMF+PGW-C.

UMTS Testing

The Mobility test can be used in the UMTS test case to test an SGSN's ability to process handoffs between emulated radio networks. You can use the Protocol drop-down list to configure the protocol stack and the type of interface (Iu-PS or Gb) for both the primary and handoff nodes, testing the SGSN's ability to handle SS7-based and IP-based protocols or its 2G and 3G compliance.

UPF Testing

Mobility Handover is used to hand over a UE from a source gNodeB to a target gNodeB using N1 (NAS-5G) interface when the UPF is unchanged. The only handoff type supported for this test is Xn. Landslide emulates the UE and both gNodeBs. The UPF is the SUT.

WiMax Testing

The Mobile Node Mobility test can be used in the WiMax Nodal test case to test a WAC's ability to process handoffs between emulated Base Stations.

CDMA2000/WiMAX Inter Working

The Inter Technology Mobility can be used in the WiMax Nodal test case to test handoff between a CDMA network and a WiMAX network, and support HA Nodal testing. The Inter Technology options are only available when the test server is licensed for both CSN Nodal and CDMA test cases.

If either Inter Technology Mobility test or Session Loading With Mobility + Inter Technology is configured, the valid MIP Scheme is CMIP.
Initial Network Type and Target FA Node are available if CDMA is licensed and either of the above test activity configurations is provisioned.
Session Loading With Mobility always indicates the Mobility Type. If CDMA is not licensed, the default value is provisioned.

Compatible Test Options

The Data Traffic option can be used to verify the SUT's ability to maintain data session integrity during handoffs. Bearer traffic using the data protocol, volume, and rate that you define is transmitted through the established sessions, adding to the real-world activity model.
The SUT Query option can be used to monitor the SUT CPU usage or to dynamically adjust the connect and disconnect rates to based on the CPU usage.

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