![8
% Received power at A without noise
SrA(d)=60-LA(d);
% Received power at B without noise
SrB(d)=60-LB(d);
% Received power at A with Gaussian noise sd=3
PrA(d)=60-LA(d)+noiseA(d) ;
% Received power at B with Gaussian noise sd=5
PrB(d)=60-LB(d)+noiseB(d);
end
figure(1)
subplot(2,1,1);
plot (PrA);
hold on
plot (PrB,'m');
axis([0 50 -110 -50]);
xlabel('distance');
ylabel('signal strength')
grid
subplot(2,1,2);
plot(SrA);
hold on
plot(SrB,'m');
axis([0 50 -110 -50]);
xlabel('distance');
ylabel('signal strength')
grid
figure(2)
plot(LA);
hold on
plot(LF);
xlabel('distance');
ylabel('signal strength')](https://image.slidesharecdn.com/mcsassignment-220223163709/85/Simulation-of-handoff-performance-using-matlab-8-320.jpg)
Simulation of handoff performance using matlab
- 1. 1 DEPARTMENT OF ELECTRONICS ENGINEERING PONDICHERRY UNIVERSITY SIMULATION OF HANDOFF PERFORMANCE USING MATLAB GUIDED BY PROF. Dr. P. SAMUNDISWARI Dept. Of Electronics Engineering PRESENTED BY ARUNKUMAR G VAISHALI K M.Tech (ECE) - Ist yr
- 2. 2 CONTENTS S. NO. TOPIC PAGE NO. 1 OBJECTIVE 3 2 INTRODUCTION 3 3 BLOCK DIAGRAM 6 4 WORKING PRINCIPLE 6 5 CODE 7 6 SIMULATION OUTPUT 9 7 ADVANTAGES 11 8 DISADVANTAGES 11 9 CONCLUSION 11 10 REFERENCES 12
- 3. 3 OBJECTIVE: • The main aim of the project is to simulate handoff performance using MATLAB code. SOFTWARE USED: • MATLAB R2020a • MATLAB an abbreviation of (“MATrix LABoratory”) is a proprietary multi-paradigm programming language and numeric computing environment developed by mathworks. INTRODUCTION: • Handoff refers to a process of transferring an ongoing call or data session from one channel connected to the core network to another. • Process of transferring a MS from one base station to another. • Also called as Handover • Handoff management is the process by which a mobile node keeps its connection active when it moves from one access point to another. STAGES IN HANDOFF: • There are three stages in a handoff process. • First, the initiation of handoff is triggered by either the mobile device,
- 4. 4 or a network agent, or the changing network conditions. • The second stage is for a new connection generation, where the network must find new resources for the handoff connection and perform any additional routing operations. • Finally, data-flow control needs to maintain the delivery of the data from the old connection path to the new connection path according to the agreed-upon QoS guarantees. REASONS FOR HANDOFFS: • Mobile device moves from one cell to another cell. • To avoid call termination: call drops. • When the capacity for connecting new calls of a given cell is used up. • In other words when the capacity of the cell is exhausted. • Interference in the channels. • When the user behaviour change like - Speed and mobility. • Interference from the small neighbouring cells. HANDOFF DETECTION: • The plane wave amplitudes, phases, and angles of arrival relative to the direction of motion are random. • These plane waves interfere and produce a varying field strength pattern. • The MS's received signal fades rapidly and deeply as it moves through this interference pattern. • By reciprocity, the BS receiver experiences the same phenomenon as the MS due to the MS motion.
- 5. 5 TYPES OF HANDOFFS: • Types of handoff depends on the movement of the mobile device, it may undergo various • Intra system handoff / horizontal handoff • Inter-system handoffs / vertical handoff ➢ Hard handoff: break before make connection ➢ Soft handoff: Make-before-break connection HANDOFF SCENARIOS: • Handoffs in homogeneous networks are referred to as intra-system handoffs. It occurs when the signal strength of the serving BS goes below a certain threshold value. • An inter-system handoff between heterogeneous networks may arise in the following scenarios. when a user moves out of the serving network and enters an overlying network, when a user connected to a network chooses to handoff to an underlying or overlaid network for his/her service requirements, when the overall load on the network is required to be distributed among different systems.
- 6. 6 HANDOFF PROTOCOLS: • Mainly there are Four types of handoff protocols which help in providing continuous and QOS-guaranteed service. ❖ Network-controlled handoff (NCHO) ❖ Mobile-assisted handoff (MAHO) ❖ Soft handoff (SHO) and ❖ Mobile-controlled handoff (MCHO) BLOCK DIAGRAM: WORKING PRINCIPLE: • Let us consider the user (MS) in the car moves away from the cell of one tower (Base Station), the signal strength of that Base Station reduces. However, the signal from another (now closer) Base Station grows, and a handoff is imminent. • One of the building blocks of cellular communication is mobility, which
- 7. 7 refers to providing users with the freedom of movement while they still are connected to the network. • Handoffs play a major role in allowing users to move across cells without the fear of being disconnected. • It is also to be noted that a handoff may also be triggered when the number of subscribers in a particular cell has already reached the cell’s maximum limit, keeping the network safe from the threat of being congested and overloaded. CODE: hte=150; %height of transmitting base station antenna in meters hre=10; %height of receiving antenna of mobile station in meters sdA=3; %standard deviation of noise for Base station A sdB=5; %standard deviation of noise for Base station B noiseA=sdA*randn(1,50); noiseB=sdB*randn(1,50); fc=input('Enter the input frequency= '); for d=1:50 % path loss calculation Between Mobile & Base station A LA(d)=(69.55+26.6*log10(fc))-(13.82*log10(hte))-((1.11*log10(fc)- 0.7)*(10)+(1.56*log10(fc)-0.8))+((44.9-6.55*log10(hte))*log10(d)); %path loss calculation Between Mobile & Base station B LB(d)=(69.55+26.6*log10(fc))-(13.82*log10(hte))-((1.11*log10(fc)- 0.7)*(10)+(1.56*log10(fc)-0.8))+((44.9-6.55*log10(hte))*log10(51-(d))); % path loss calculation for free space model LF(d)=32.4+20*log10(fc)+20*log10(d);
- 8. 8 % Received power at A without noise SrA(d)=60-LA(d); % Received power at B without noise SrB(d)=60-LB(d); % Received power at A with Gaussian noise sd=3 PrA(d)=60-LA(d)+noiseA(d) ; % Received power at B with Gaussian noise sd=5 PrB(d)=60-LB(d)+noiseB(d); end figure(1) subplot(2,1,1); plot (PrA); hold on plot (PrB,'m'); axis([0 50 -110 -50]); xlabel('distance'); ylabel('signal strength') grid subplot(2,1,2); plot(SrA); hold on plot(SrB,'m'); axis([0 50 -110 -50]); xlabel('distance'); ylabel('signal strength') grid figure(2) plot(LA); hold on plot(LF); xlabel('distance'); ylabel('signal strength')
- 9. 9 SIMULATION OUTPUT: Enter the input frequency= 300
- 10. 10 Enter the input frequency= 10000
- 11. 11 ADVANTAGES OF SOFT HANDOFF: • Provides better Quality Assurance as a channel • More than one repeater can send and receive signals to transmit signals to and from mobiles, increasing transfer speed and Delay is very low • Soft Handover Gain: Soft Handoffs lead to an increase in the signal to interference ratio, without performance loss. DISADVANTAGES OF SOFT HANDOFF: • Only supported for phones that employ CDMA/ WCDMA, and cannot be implemented in LTE or GSM. • Costlier to implement than Hard Handoff as a channel is always wasted by being the backup. ADVANTAGES OF HARD HANDOFF: • Hard Handovers are cheaper as they require only one channel to be active at a time. • Hard Handoffs are generally implemented more than Soft Handoffs because of their efficiency. DISADVANTAGES OF HARD HANDOFF: • A delay is often experienced while switching, but it generally is quite small such that the user does not experience it. CONCLUSION: • In this assignment we have done the performance of handoff using matlab code. • Soft Handoffs are generally used in MS that employ Code Division Multiple Access (CDMA) or Wideband CDMA (WCDMA), and its
- 12. 12 associated services, and also in applications that require a continuous connection throughout, possibly for security purposes. • Hard Handoffs are implemented in TDMA devices, used in applications that can afford slight delays, such as Internet, and WiMAX. REFERENCE: • https://www.slideshare.net/ajal4u/handoff • https://slideplayer.com/slide/12801780/ • https://technobyte.org/handoff-types-mobile-communication- wireless-network/ • https://docplayer.net/amp/5843657-The-design-objective-of-early- mobile-radio-systems-was-to-achieve-a-large-coverage.html • https://technobyte.org/handoff-types-mobile-communication- wireless-network/ • https://www.scribd.com/document/70971812/simulation-of-handoff- performance-in-cellular-mobile-communication