A Discrete-Event Network Simulator
API
a3-rsrp-handover-algorithm.cc
Go to the documentation of this file.
1/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
2/*
3 * Copyright (c) 2013 Budiarto Herman
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Budiarto Herman <budiarto.herman@magister.fi>
19 *
20 */
21
23#include <ns3/log.h>
24#include <ns3/double.h>
25#include <ns3/lte-common.h>
26#include <algorithm>
27#include <list>
28
29namespace ns3 {
30
31NS_LOG_COMPONENT_DEFINE ("A3RsrpHandoverAlgorithm");
32
33NS_OBJECT_ENSURE_REGISTERED (A3RsrpHandoverAlgorithm);
34
35
37 : m_handoverManagementSapUser (0)
38{
39 NS_LOG_FUNCTION (this);
41}
42
43
45{
46 NS_LOG_FUNCTION (this);
47}
48
49
52{
53 static TypeId tid = TypeId ("ns3::A3RsrpHandoverAlgorithm")
55 .SetGroupName ("Lte")
56 .AddConstructor<A3RsrpHandoverAlgorithm> ()
57 .AddAttribute ("Hysteresis",
58 "Handover margin (hysteresis) in dB "
59 "(rounded to the nearest multiple of 0.5 dB)",
60 DoubleValue (3.0),
62 MakeDoubleChecker<uint8_t> (0.0, 15.0)) // Hysteresis IE value range is [0..30] as per Section 6.3.5 of 3GPP TS 36.331
63 .AddAttribute ("TimeToTrigger",
64 "Time during which neighbour cell's RSRP "
65 "must continuously higher than serving cell's RSRP "
66 "in order to trigger a handover",
67 TimeValue (MilliSeconds (256)), // 3GPP time-to-trigger median value as per Section 6.3.5 of 3GPP TS 36.331
70 ;
71 return tid;
72}
73
74
75void
77{
78 NS_LOG_FUNCTION (this << s);
80}
81
82
85{
86 NS_LOG_FUNCTION (this);
88}
89
90
91void
93{
94 NS_LOG_FUNCTION (this);
95
97 NS_LOG_LOGIC (this << " requesting Event A3 measurements"
98 << " (hysteresis=" << (uint16_t) hysteresisIeValue << ")"
99 << " (ttt=" << m_timeToTrigger.As (Time::MS) << ")");
100
101 LteRrcSap::ReportConfigEutra reportConfig;
103 reportConfig.a3Offset = 0;
104 reportConfig.hysteresis = hysteresisIeValue;
106 reportConfig.reportOnLeave = false;
110
112}
113
114
115void
117{
118 NS_LOG_FUNCTION (this);
120}
121
122
123void
125 LteRrcSap::MeasResults measResults)
126{
127 NS_LOG_FUNCTION (this << rnti << (uint16_t) measResults.measId);
128
129 if (std::find (begin (m_measIds), end (m_measIds), measResults.measId) == std::end (m_measIds))
130 {
131 NS_LOG_WARN ("Ignoring measId " << (uint16_t) measResults.measId);
132 return;
133 }
134
135 if (measResults.haveMeasResultNeighCells
136 && !measResults.measResultListEutra.empty ())
137 {
138 uint16_t bestNeighbourCellId = 0;
139 uint8_t bestNeighbourRsrp = 0;
140
141 for (std::list <LteRrcSap::MeasResultEutra>::iterator it = measResults.measResultListEutra.begin ();
142 it != measResults.measResultListEutra.end ();
143 ++it)
144 {
145 if (it->haveRsrpResult)
146 {
147 if ((bestNeighbourRsrp < it->rsrpResult)
148 && IsValidNeighbour (it->physCellId))
149 {
150 bestNeighbourCellId = it->physCellId;
151 bestNeighbourRsrp = it->rsrpResult;
152 }
153 }
154 else
155 {
156 NS_LOG_WARN ("RSRP measurement is missing from cell ID " << it->physCellId);
157 }
158 }
159
160 if (bestNeighbourCellId > 0)
161 {
162 NS_LOG_LOGIC ("Trigger Handover to cellId " << bestNeighbourCellId);
163 NS_LOG_LOGIC ("target cell RSRP " << (uint16_t) bestNeighbourRsrp);
164 NS_LOG_LOGIC ("serving cell RSRP " << (uint16_t) measResults.measResultPCell.rsrpResult);
165
166 // Inform eNodeB RRC about handover
168 bestNeighbourCellId);
169 }
170 }
171 else
172 {
173 NS_LOG_WARN (this << " Event A3 received without measurement results from neighbouring cells");
174 }
175
176} // end of DoReportUeMeas
177
178
179bool
181{
182 NS_LOG_FUNCTION (this << cellId);
183
190 return true;
191}
192
193
194} // end of namespace ns3
Implementation of the strongest cell handover algorithm, based on RSRP measurements and Event A3.
virtual void DoInitialize()
Initialize() implementation.
bool IsValidNeighbour(uint16_t cellId)
Determines if a neighbour cell is a valid destination for handover.
double m_hysteresisDb
The Hysteresis attribute.
LteHandoverManagementSapUser * m_handoverManagementSapUser
Interface to the eNodeB RRC instance.
static TypeId GetTypeId()
Get the type ID.
LteHandoverManagementSapProvider * m_handoverManagementSapProvider
Receive API calls from the eNodeB RRC instance.
Time m_timeToTrigger
The TimeToTrigger attribute.
friend class MemberLteHandoverManagementSapProvider< A3RsrpHandoverAlgorithm >
let the forwarder class access the protected and private members
A3RsrpHandoverAlgorithm()
Creates a strongest cell handover algorithm instance.
virtual void DoDispose()
Destructor implementation.
std::vector< uint8_t > m_measIds
The expected measurement identity for A3 measurements.
void DoReportUeMeas(uint16_t rnti, LteRrcSap::MeasResults measResults)
Implementation of LteHandoverManagementSapProvider::ReportUeMeas.
virtual LteHandoverManagementSapProvider * GetLteHandoverManagementSapProvider()
Export the "provider" part of the Handover Management SAP interface.
virtual void SetLteHandoverManagementSapUser(LteHandoverManagementSapUser *s)
Set the "user" part of the Handover Management SAP interface that this handover algorithm instance wi...
This class can be used to hold variables of floating point type such as 'double' or 'float'.
Definition: double.h:41
static uint8_t ActualHysteresis2IeValue(double hysteresisDb)
Returns the IE value of hysteresis.
Definition: lte-common.cc:304
The abstract base class of a handover algorithm that operates using the Handover Management SAP inter...
Service Access Point (SAP) offered by the handover algorithm instance to the eNodeB RRC instance.
Service Access Point (SAP) offered by the eNodeB RRC instance to the handover algorithm instance.
virtual void TriggerHandover(uint16_t rnti, uint16_t targetCellId)=0
Instruct the eNodeB RRC entity to prepare a handover.
virtual std::vector< uint8_t > AddUeMeasReportConfigForHandover(LteRrcSap::ReportConfigEutra reportConfig)=0
Request a certain reporting configuration to be fulfilled by the UEs attached to the eNodeB entity.
virtual void DoInitialize(void)
Initialize() implementation.
Definition: object.cc:353
@ MS
millisecond
Definition: nstime.h:115
int64_t GetMilliSeconds(void) const
Get an approximation of the time stored in this instance in the indicated unit.
Definition: nstime.h:383
TimeWithUnit As(const enum Unit unit=Time::AUTO) const
Attach a unit to a Time, to facilitate output in a specific unit.
Definition: time.cc:418
AttributeValue implementation for Time.
Definition: nstime.h:1308
a unique identifier for an interface.
Definition: type-id.h:59
TypeId SetParent(TypeId tid)
Set the parent TypeId.
Definition: type-id.cc:922
Ptr< const AttributeAccessor > MakeDoubleAccessor(T1 a1)
Definition: double.h:42
Ptr< const AttributeAccessor > MakeTimeAccessor(T1 a1)
Definition: nstime.h:1309
#define NS_LOG_COMPONENT_DEFINE(name)
Define a Log component with a specific name.
Definition: log.h:205
#define NS_LOG_LOGIC(msg)
Use NS_LOG to output a message of level LOG_LOGIC.
Definition: log.h:289
#define NS_LOG_FUNCTION(parameters)
If log level LOG_FUNCTION is enabled, this macro will output all input parameters separated by ",...
#define NS_LOG_WARN(msg)
Use NS_LOG to output a message of level LOG_WARN.
Definition: log.h:265
#define NS_OBJECT_ENSURE_REGISTERED(type)
Register an Object subclass with the TypeId system.
Definition: object-base.h:45
Time MilliSeconds(uint64_t value)
Construct a Time in the indicated unit.
Definition: nstime.h:1252
Every class exported by the ns3 library is enclosed in the ns3 namespace.
Ptr< const AttributeChecker > MakeTimeChecker(const Time min, const Time max)
Helper to make a Time checker with bounded range.
Definition: time.cc:522
uint8_t rsrpResult
the RSRP result
Definition: lte-rrc-sap.h:638
MeasResults structure.
Definition: lte-rrc-sap.h:680
uint8_t measId
measure ID
Definition: lte-rrc-sap.h:681
bool haveMeasResultNeighCells
have measure result neighbor cells
Definition: lte-rrc-sap.h:683
std::list< MeasResultEutra > measResultListEutra
measure result list eutra
Definition: lte-rrc-sap.h:684
MeasResultPCell measResultPCell
measurement result primary cell
Definition: lte-rrc-sap.h:682
Specifies criteria for triggering of an E-UTRA measurement reporting event.
Definition: lte-rrc-sap.h:362
bool reportOnLeave
Indicates whether or not the UE shall initiate the measurement reporting procedure when the leaving c...
Definition: lte-rrc-sap.h:385
@ RSRP
Reference Signal Received Power.
Definition: lte-rrc-sap.h:406
uint8_t hysteresis
Parameter used within the entry and leave condition of an event triggered reporting condition....
Definition: lte-rrc-sap.h:391
enum ns3::LteRrcSap::ReportConfigEutra::@68 reportInterval
Report interval enumeration.
enum ns3::LteRrcSap::ReportConfigEutra::@65 eventId
Event enumeration.
enum ns3::LteRrcSap::ReportConfigEutra::@66 triggerQuantity
Trigger type enumeration.
@ EVENT_A3
Event A3: Neighbour becomes amount of offset better than PCell.
Definition: lte-rrc-sap.h:375
int8_t a3Offset
Offset value for Event A3. An integer between -30 and 30. The actual value is (value * 0....
Definition: lte-rrc-sap.h:388
uint16_t timeToTrigger
Time during which specific criteria for the event needs to be met in order to trigger a measurement r...
Definition: lte-rrc-sap.h:394