In specific, vertical handover/handoff is used to create a connection to the supporting network/infrastructure. As a result, the node mobility will be smooth and seamless. For instance: to access the internet, the laptop can use both cellular technology (4G / 5G) and WLAN technology. 

This article talks about the research and development guidelines to Vertical Handover Simulation NS3!!!

What is a vertical handover explain with an everyday example?

In recent times, the intersections of heterogeneous networks on several real-world scenarios are increasing widely. For instance: smartphones usually connect with different interfaces of different network technologies. At that time, it requires to changeover on respective networks. For this purpose, vertical handover (VHO) techniques are used to make this seamless without interruption. Here, we have given you the designing information for different VHO applications in various scenarios.

Vertical Handover Applications

• Streaming
  • Design CBR traffic for video streaming among server and mobile node
  • Video streaming time reach up to entire simulation time
  • Data Transfer Rate – 1 Mbits / sec
• Conversational
  • Design CBR voice traffic for conversational traffic
  • Voice call time reach up to entire simulation time
  • Mobile node of client traffic – 84 Kbits / sec
• Background
  • Design E-mail traffic for contextual traffic
  • Email size – 25 to 100 Kb
  • Email traffic time reach up to entire simulation time
• Interactive
  • Design web surfing traffic for responsive application
  • Web surfing sessions (time) reach up to entire simulation time
  • Web page size – 100 to 500 kb

Now, we can see about the Vertical Handover Simulation using NS3 tool. Generally, the mobile nodes of the heterogeneous network are freely wandering over different networks. For instance: Wi-Max, UMTS, and Wi-Fi. Here, the mobile nodes select the benefited path based on certain metrics as bandwidth, RSS, etc. This evaluation process takes place in the MATLAB tool and forwards the results to NS3 for vertical handover simulation.    

One of the best tools to achieve the expected result in vertical handover is NS3. It is composed of special modules for handovers that overcome the OSFY related problems. 

 Also, it is flexible to design and simulate wireless heterogeneous networking models. Now, we can see how the Vertical Handover Simulation NS3 is performed between LiFi and WiFi

Vertical Handover between LiFi and WiFi

The independent LiFi support only the fixed nodes since the user majorly faces frequency outage problems in mobile nodes. To solve this problem, efficient handover schemes are required. So, it is easy to connect users to suitable Access Points (AP) in the network. In this, the current AP discharges the grabbed resources of the mobile node. Then the new network allocates resources to that mobile node based on their service request. Basically, there are two types of networks in LiFi and WiFi systems.

 And, they are given as follows:

• Vertical Handover (VHO)
  • In this, the user switch between the Aps of two different networks
  • For instance: Li-Fi to Wi-Fi
• Horizontal Handover (HHO)
  • In this, the user switch between the APs in the same network
  • For instance: Li-Fi to Li-Fi / Wi-Fi to Wi-Fi

Though several network simulators were already developed and still developing at present, we prefer NS3 simulators for vertical handover for the following reasons. Let’s have a look over them in the below points, 

Why do we choose NS3 for vertical handover?

• Adaptable to incorporate with real networks using handover protocols which are bundled with ns-3
• In comparison with other network simulators (NS2, GloMoSim, OMNeT ++), it is more efficient by means of memory
• Includes 5G NR modules to support NS3 5G enabled heterogeneous networks and LTE integration
• Comprises in-built Wi-Fi and LTE modules to support hybrid technologies

In addition, the NS3 simulator is sophisticated with several modules and libraries specially meant for the vertical handover, here we have given you some widely used NS3 modules followed by NS3 model libraries for vertical handover. We support not only these modules/libraries but also others based on your handpicked wireless simulation that incorporated in your vertical handover simulation NS3 projects.

NS3 Modules for Vertical handover

• Mobility Module
• Internet Module
• 5G mmWave Module
• LTE Module
• WiFi Module

NS3 Model Libraries for Vertical Handover

• Ns3::LteHelper::Scheduler
• Ns3::PhyStatsCalculator::DIRsrpSinrFilename
• Ns3::LteHelper::HandoverAlgorithm
• Ns3::PhyStatsCalculator::UISinrFileName
• Ns3::LteHelper::UseIdealRrc
• Ns3::RadioBEarerStatsCalculator::DIRIcOutputFilename
• Ns3::RadioBEarerStatsCalculator::UIRIcOutputFilename

Next, we can see the execution procedure of vertical handover using the NS3 simulation tool. Here, we have given only the common steps of VHO. Further, this may vary based on the selected techniques and algorithms of the VHD process. Overall, we have a goal to achieve the best vertical handover decision for choosing the best-benefited network switching. 

Steps for Vertical handover using NS3

• At first, configure the network topology
• Then, use mobile station for monitoring the nearer stations
• Next, again choose the new cells
• After that, take decision on handover and execute
• At last, reconfigure the network

How to configure the topology for vertical handover using NS3?

            From the above section, you can understand the general steps to execute the vertical handover process. Now, we can set the configuration of user equipment measurement (i.e., topology). Since it is one of the essential parts in NS3based VHO execution. 

Configure UE measurements

With help of a vertical handover algorithm, one can configure the UE measurement while simulation. Further, the users also have the opportunities to configure their own events in several methods. And, few are them are given in the followings, 

• Design and develop a new HO algorithm
• Explicitly configure with eNodeB RRC entity
• Configure already defined HO algorithm

By using eNodeB RRC entity, we can instigate the handover algorithm in a systematic way. Here, the users may create their own algorithm or select an optimal predefined algorithm and configure it appropriately in the simulation. By the by, the handpicked algorithm can also provide the different properties/attributes for configuration. For instance: 

• lteHelper->SetHandoverAlgorithmAttribute (“NeighbourCellOffset”, UintegerValue (2));
• lteHelper->SetHandoverAlgorithmAttribute (“ServingCellThreshold”, UintegerValue (25));

Our developers are adept to develop own algorithm based on project requirements. So, we provide comprehensive guidance on selecting/creating handover algorithms in an effective manner. Further, below we have given you that how the handover process is initiated through the LTE module. For instance, handover initiated using LTE module as follows. 

X2-based handover

As already mentioned in the 3GPP protocol, the handover technique takes the responsibility of connectivity switch on UEs and keep always them in CONNECTED mode. Here, it encloses source eNodeB and the target eNodeB for further process. There are two most important steps in executing X2-based handover. One is enabling the EPC in simulation and the other is configuring the two eNodeBs in simulation code.

ENodeBs Configuration Command: lteHelper->AddX2Interface (enbNodes);

How to improve the performance of Handover in NS3?

Now, we can move on to the most important phase of handover that is performance enhancement. One of the major reasons for handover failure is transmission error of handover. Similarly, it has so many design issues in the handover procedure. Here, our experts have given you effective measures to increase the performance of handover in simulation.

• Achieve high SINR in each UE to minimize transmission error
• To simplify HO process, consider S1 and X2 interfaces are stable to focus on RRC protocol
  • S1 interface – Among target eNodeB and SGW/PGW
  • X2 interface – Among source eNodeB and target eNodeB
  • RRC protocol – Among UE and eNodeBs
• Also, concentrate on random access method (vulnerable to channel state degradation)
• Eliminate the high-delay handovers (Prior to low SINR of UEs, the handover process should takes place else UEs will not receive handover order)
• Design effective network topology to minimize coverage hole in network
• Handover algorithms need to have feature for controlling decision-making
• For instance: A2-A4-RSRQ and shorter time-to-trigger handover algorithms have high threshold for earlier handover decision
  • Use speed of UE mobility as major parameter to execute HO prior
• Other significant parameters for handover simulation in NS3 are given as follows,
  • Packet Size – 1000 bytes
  • HO Algorithm – A3Rsrp
  • Sum of Resource Block – 15
  • Mobility – Random Walk 2D
  • Sum of Traffic Source – 2 to 10
  • TCP Traffic Type – Cubic
  • RLC Buffer Size – 100 to 200
  • eNB Transmission Mode – SISO
  • Node Mobility Velocity – 20 m/s
  • Data Rate of Application – 100 Mbps
  • Overall Simulation Duration – 100 s
  • Capacity of Wired Connection – 10 Mbps
  • Latency of Wired Connection – 50 ms
  • Simulation Area – 5 Km Radius (Multi / Single Cell)
  • Application Start and End Time – From 0.1s to 100s

In point of fact, the main motive of the vertical handover techniques and algorithms is to achieve seamless connectivity, limited handovers, and low handover delay during simulation. In order to achieve all these elements, an effective vertical handover decision needs to be taken. For that, we need to focus on following quality of service (QoS) metrics which are essential for decision algorithms.   

How to measure the performance of vertical handover?

• Jitter
• Packet Loss Ratio (PLR)
• Throughput
• Handover Delay
• Latency
• Bit Error Rate

The other factors that influence the network performance are environmental state, service provider, access technology, user mobility, network operator, and varying performance metrics. All these things are taken into consideration for evaluating the overall efficiency of the proposed VHO simulation in the networking model.

On the whole, we help you in designing, developing, and simulating the vertical handover techniques in the NS3 simulation tool. Further, we also provide you with project topics related to Vertical handover simulation ns3 for both research scholars and students (final year projects). So, create a bond with us to create masterpiece work in your networking research journey.

We just handover all your issues for your vertical handover projects to our top experts!!!

Do you need a change of mind for your research topic in NS3? Feel free to approach us!!!