A Discrete-Event Network Simulator
API
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Properties Friends Macros Groups Pages
ns3::A3RsrpHandoverAlgorithm Class Reference

Implementation of the strongest cell handover algorithm, based on RSRP measurements and Event A3. More...

#include <a3-rsrp-handover-algorithm.h>

+ Inheritance diagram for ns3::A3RsrpHandoverAlgorithm:
+ Collaboration diagram for ns3::A3RsrpHandoverAlgorithm:

Public Member Functions

 A3RsrpHandoverAlgorithm ()
 Creates a strongest cell handover algorithm instance. More...
 
virtual ~A3RsrpHandoverAlgorithm ()
 
virtual
LteHandoverManagementSapProvider
GetLteHandoverManagementSapProvider ()
 Export the "provider" part of the Handover Management SAP interface. More...
 
virtual void SetLteHandoverManagementSapUser (LteHandoverManagementSapUser *s)
 Set the "user" part of the Handover Management SAP interface that this handover algorithm instance will interact with. More...
 
- Public Member Functions inherited from ns3::LteHandoverAlgorithm
 LteHandoverAlgorithm ()
 
virtual ~LteHandoverAlgorithm ()
 
- Public Member Functions inherited from ns3::Object
 Object ()
 
virtual ~Object ()
 
void AggregateObject (Ptr< Object > other)
 
void Dispose (void)
 Run the DoDispose methods of this object and all the objects aggregated to it. More...
 
AggregateIterator GetAggregateIterator (void) const
 
virtual TypeId GetInstanceTypeId (void) const
 
template<typename T >
Ptr< T > GetObject (void) const
 
template<typename T >
Ptr< T > GetObject (TypeId tid) const
 
void Initialize (void)
 This method calls the virtual DoInitialize method on all the objects aggregated to this object. More...
 
- Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
 SimpleRefCount ()
 Constructor. More...
 
 SimpleRefCount (const SimpleRefCount &o)
 Copy constructor. More...
 
uint32_t GetReferenceCount (void) const
 Get the reference count of the object. More...
 
SimpleRefCountoperator= (const SimpleRefCount &o)
 Assignment. More...
 
void Ref (void) const
 Increment the reference count. More...
 
void Unref (void) const
 Decrement the reference count. More...
 
- Public Member Functions inherited from ns3::ObjectBase
virtual ~ObjectBase ()
 Virtual destructor. More...
 
void GetAttribute (std::string name, AttributeValue &value) const
 
bool GetAttributeFailSafe (std::string name, AttributeValue &attribute) const
 
void SetAttribute (std::string name, const AttributeValue &value)
 
bool SetAttributeFailSafe (std::string name, const AttributeValue &value)
 
bool TraceConnect (std::string name, std::string context, const CallbackBase &cb)
 
bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 
bool TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
 
bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
 

Static Public Member Functions

static TypeId GetTypeId ()
 
- Static Public Member Functions inherited from ns3::LteHandoverAlgorithm
static TypeId GetTypeId ()
 
- Static Public Member Functions inherited from ns3::Object
static TypeId GetTypeId (void)
 Register this type. More...
 
- Static Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
static void Cleanup (void)
 Noop. More...
 
- Static Public Member Functions inherited from ns3::ObjectBase
static TypeId GetTypeId (void)
 Get the type ID. More...
 

Protected Member Functions

virtual void DoDispose ()
 This method is called by Object::Dispose or by the object's destructor, whichever comes first. More...
 
virtual void DoInitialize ()
 This method is called only once by Object::Initialize. More...
 
void DoReportUeMeas (uint16_t rnti, LteRrcSap::MeasResults measResults)
 Implementation of LteHandoverManagementSapProvider::ReportUeMeas. More...
 
- Protected Member Functions inherited from ns3::Object
 Object (const Object &o)
 
virtual void NotifyNewAggregate (void)
 This method is invoked whenever two sets of objects are aggregated together. More...
 
- Protected Member Functions inherited from ns3::ObjectBase
void ConstructSelf (const AttributeConstructionList &attributes)
 
virtual void NotifyConstructionCompleted (void)
 This method is invoked once all member attributes have been initialized. More...
 

Private Member Functions

bool IsValidNeighbour (uint16_t cellId)
 

Private Attributes

LteHandoverManagementSapProviderm_handoverManagementSapProvider
 
LteHandoverManagementSapUserm_handoverManagementSapUser
 
double m_hysteresisDb
 
uint8_t m_measId
 
Time m_timeToTrigger
 

Friends

class MemberLteHandoverManagementSapProvider< A3RsrpHandoverAlgorithm >
 

Detailed Description

Implementation of the strongest cell handover algorithm, based on RSRP measurements and Event A3.

The algorithm utilizes Event A3 (Section 5.5.4.4 of 3GPP TS 36.331) UE measurements and the Reference Signal Reference Power (RSRP). It is defined as the event when the UE perceives that a neighbour cell's RSRP is better than the serving cell's RSRP.

Handover margin (a.k.a. hysteresis) and time-to-trigger (TTT) can be configured to delay the event triggering. The values of these parameters apply to all attached UEs.

The following code snippet is an example of using and configuring the handover algorithm in a simulation program:

Ptr<LteHelper> lteHelper = CreateObject<LteHelper> ();

NodeContainer enbNodes;
// configure the nodes here...

lteHelper->SetHandoverAlgorithmType ("ns3::A3RsrpHandoverAlgorithm");
lteHelper->SetHandoverAlgorithmAttribute ("Hysteresis",
                                          DoubleValue (3.0));
lteHelper->SetHandoverAlgorithmAttribute ("TimeToTrigger",
                                          TimeValue (MilliSeconds (256)));
NetDeviceContainer enbLteDevs = lteHelper->InstallEnbDevice (enbNodes);
Note
Setting the handover algorithm type and attributes after the call to LteHelper::InstallEnbDevice does not have any effect to the devices that have already been installed.

Config Paths

ns3::A3RsrpHandoverAlgorithm is accessible through the following paths with Config::Set and Config::Connect:

  • /NodeList/[i]/DeviceList/[i]/$ns3::LteEnbNetDevice/LteHandoverAlgorithm/$ns3::A3RsrpHandoverAlgorithm
  • /NodeList/[i]/DeviceList/[i]/$ns3::LteNetDevice/$ns3::LteEnbNetDevice/LteHandoverAlgorithm/$ns3::A3RsrpHandoverAlgorithm

Attributes

  • Hysteresis: Handover margin (hysteresis) in dB (rounded to the nearest multiple of 0.5 dB)
  • TimeToTrigger: Time during which neighbour cell's RSRP must continuously higher than serving cell's RSRP in order to trigger a handover
    • Set with class: ns3::TimeValue
    • Underlying type: Time –9223372036854775808.0ns:+9223372036854775807.0ns
    • Initial value: +256000000.0ns
    • Flags: construct write read

No TraceSources are defined for this type.

Definition at line 65 of file a3-rsrp-handover-algorithm.h.

Constructor & Destructor Documentation

ns3::A3RsrpHandoverAlgorithm::A3RsrpHandoverAlgorithm ( )

Creates a strongest cell handover algorithm instance.

Definition at line 35 of file a3-rsrp-handover-algorithm.cc.

References m_handoverManagementSapProvider, and NS_LOG_FUNCTION.

ns3::A3RsrpHandoverAlgorithm::~A3RsrpHandoverAlgorithm ( )
virtual

Definition at line 43 of file a3-rsrp-handover-algorithm.cc.

References NS_LOG_FUNCTION.

Member Function Documentation

void ns3::A3RsrpHandoverAlgorithm::DoDispose ( void  )
protectedvirtual

This method is called by Object::Dispose or by the object's destructor, whichever comes first.

Subclasses are expected to implement their real destruction code in an overriden version of this method and chain up to their parent's implementation once they are done. i.e., for simplicity, the destructor of every subclass should be empty and its content should be moved to the associated DoDispose method.

It is safe to call GetObject from within this method.

Reimplemented from ns3::LteHandoverAlgorithm.

Definition at line 114 of file a3-rsrp-handover-algorithm.cc.

References m_handoverManagementSapProvider, and NS_LOG_FUNCTION.

void ns3::A3RsrpHandoverAlgorithm::DoInitialize ( void  )
protectedvirtual

This method is called only once by Object::Initialize.

If the user calls Object::Initialize multiple times, DoInitialize is called only the first time.

Subclasses are expected to override this method and chain up to their parent's implementation once they are done. It is safe to call GetObject and AggregateObject from within this method.

Reimplemented from ns3::Object.

Definition at line 90 of file a3-rsrp-handover-algorithm.cc.

References ns3::EutranMeasurementMapping::ActualHysteresis2IeValue(), ns3::LteHandoverManagementSapUser::AddUeMeasReportConfigForHandover(), ns3::Object::DoInitialize(), ns3::LteRrcSap::ReportConfigEutra::EVENT_A3, ns3::LteRrcSap::ReportConfigEutra::eventId, ns3::Time::GetMilliSeconds(), m_handoverManagementSapUser, m_hysteresisDb, m_measId, m_timeToTrigger, ns3::LteRrcSap::ReportConfigEutra::MS1024, NS_LOG_FUNCTION, NS_LOG_LOGIC, and ns3::LteRrcSap::ReportConfigEutra::RSRP.

+ Here is the call graph for this function:

void ns3::A3RsrpHandoverAlgorithm::DoReportUeMeas ( uint16_t  rnti,
LteRrcSap::MeasResults  measResults 
)
protectedvirtual

Implementation of LteHandoverManagementSapProvider::ReportUeMeas.

Parameters
rntiRadio Network Temporary Identity, an integer identifying the UE where the report originates from
measResultsa single report of one measurement identity

Implements ns3::LteHandoverAlgorithm.

Definition at line 122 of file a3-rsrp-handover-algorithm.cc.

References ns3::LteRrcSap::MeasResults::haveMeasResultNeighCells, IsValidNeighbour(), m_handoverManagementSapUser, m_measId, ns3::LteRrcSap::MeasResults::measId, ns3::LteRrcSap::MeasResults::measResultListEutra, NS_LOG_FUNCTION, NS_LOG_LOGIC, NS_LOG_WARN, ns3::LteRrcSap::MeasResults::rsrpResult, and ns3::LteHandoverManagementSapUser::TriggerHandover().

+ Here is the call graph for this function:

LteHandoverManagementSapProvider * ns3::A3RsrpHandoverAlgorithm::GetLteHandoverManagementSapProvider ( )
virtual

Export the "provider" part of the Handover Management SAP interface.

Returns
the reference to the "provider" part of the interface, typically to be kept by an LteEnbRrc instance

Implements ns3::LteHandoverAlgorithm.

Definition at line 82 of file a3-rsrp-handover-algorithm.cc.

References m_handoverManagementSapProvider, and NS_LOG_FUNCTION.

TypeId ns3::A3RsrpHandoverAlgorithm::GetTypeId ( void  )
static

Definition at line 50 of file a3-rsrp-handover-algorithm.cc.

References m_hysteresisDb, m_timeToTrigger, ns3::MakeTimeChecker(), and ns3::TypeId::SetParent().

+ Here is the call graph for this function:

bool ns3::A3RsrpHandoverAlgorithm::IsValidNeighbour ( uint16_t  cellId)
private
Todo:
In the future, this function can be expanded to validate whether the neighbour cell is a valid target cell, e.g., taking into account the NRT in ANR and whether it is a CSG cell with closed access.

Definition at line 179 of file a3-rsrp-handover-algorithm.cc.

References NS_LOG_FUNCTION.

Referenced by DoReportUeMeas().

+ Here is the caller graph for this function:

void ns3::A3RsrpHandoverAlgorithm::SetLteHandoverManagementSapUser ( LteHandoverManagementSapUser s)
virtual

Set the "user" part of the Handover Management SAP interface that this handover algorithm instance will interact with.

Parameters
sa reference to the "user" part of the interface, typically a member of an LteEnbRrc instance

Implements ns3::LteHandoverAlgorithm.

Definition at line 74 of file a3-rsrp-handover-algorithm.cc.

References m_handoverManagementSapUser, NS_LOG_FUNCTION, and s.

Friends And Related Function Documentation

Member Data Documentation

LteHandoverManagementSapProvider* ns3::A3RsrpHandoverAlgorithm::m_handoverManagementSapProvider
private
LteHandoverManagementSapUser* ns3::A3RsrpHandoverAlgorithm::m_handoverManagementSapUser
private
double ns3::A3RsrpHandoverAlgorithm::m_hysteresisDb
private

Definition at line 101 of file a3-rsrp-handover-algorithm.h.

Referenced by DoInitialize(), and GetTypeId().

uint8_t ns3::A3RsrpHandoverAlgorithm::m_measId
private

Definition at line 98 of file a3-rsrp-handover-algorithm.h.

Referenced by DoInitialize(), and DoReportUeMeas().

Time ns3::A3RsrpHandoverAlgorithm::m_timeToTrigger
private

Definition at line 102 of file a3-rsrp-handover-algorithm.h.

Referenced by DoInitialize(), and GetTypeId().


The documentation for this class was generated from the following files: