ns2단기강좌-2011-10-10 (1).pptx
TRANSCRIPT
![Page 1: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/1.jpg)
1
ns-2 를 이용한 최신 네트워크 시뮬레이션
NS-2 의 802_11Ext 클래스를 활용한 무선 네트워크 시뮬레이션
강 문 수 ([email protected])
네트워크 구조 및 분석 연구실조선대학교 컴퓨터공학부
2011 년 10 월 26 일
![Page 2: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/2.jpg)
Contents
• 1. IEEE 802.11 개념 및 알고리즘 설명• 2. 기존 NS2 의 802.11 구현의 문제점 및 성능
오류• 3. 802_11Ext 클래스 소개 및 구조 분석• 4. 시뮬레이션 예제• 5. 802_11Ext 을 기반으로 directional antenna
구현 및 확장 예제
2
![Page 3: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/3.jpg)
1. IEEE 802.11 MAC 동작 원리
- CARRIER SENSING- BINARY EXPONENTIAL BACKOFF 등
3
![Page 4: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/4.jpg)
Why MAC (Media Access Protocol)?
• Single pair transmission
• Multiple pairs transmission
encoding modulation decodingdemodulation TX media
Coaxial cable, Ethernet, WiFi, Optical Fiber, VLC
A sender A receiver
1
3
4
2
5
What happens if there are a lot of simultaneous transmission over the same TX media ?
The characteristics of TX Media:Collision free or Collision ?
![Page 5: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/5.jpg)
TDMA
• Time Division Multiple Access– Time synchronization and scheduling– Centralized coordination
1
3
4
2
5
1 2 3 4 5 1 2
A single TDMA round
![Page 6: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/6.jpg)
RMA
• Random Multiple Access– No central coordination– Packet generation is a random process.– Assuming propagation and transmission delay are so
small.
1
3
4
2
5
![Page 7: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/7.jpg)
Carrier Sensing
Node A
Node B
Node A
Node Bdelayed
Carrier sensing
![Page 8: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/8.jpg)
Carrier SensingData
Ready
8
![Page 9: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/9.jpg)
Carrier Sensing is not enough.
Node A
Node B
Node C
Node A
Node B
Node C
collision
![Page 10: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/10.jpg)
Random Backoff
Node A
Node B
Node C
collision
Node A
Node B
Node C
Random backoff(Contention window[0:31])
![Page 11: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/11.jpg)
Random Backoff
![Page 12: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/12.jpg)
Hidden/Exposed node problem
• WiFi– Not single hop transmission
– Collision Avoidance
Hidden node problem
Exposed node problem
![Page 13: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/13.jpg)
Collision Avoidance
• RTS/CTS exchange– For the hidden node
– For the exposed node
![Page 14: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/14.jpg)
Reliability
• Wireless links are prone to errors.– High packet loss rate detrimental to transport layer
performance. – Mechanism needed to reduce packet rate experienced
by upper layers.
• A simple solution– Acknowledgment (ACK)– Retransmission
14
A B
data
ACK
![Page 15: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/15.jpg)
A single frame transmission
15
![Page 16: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/16.jpg)
Congestion Control
• If there are so many competitors, then?
• BEB (Binary Exponential Backoff)– Doubled contention window size (32 64 128)
16
Node A
Node B
Node C
Random backoff(Contention window[0:31])
13
4
2
5
![Page 17: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/17.jpg)
![Page 18: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/18.jpg)
Other MAC Protocols Issues:Fairness
![Page 19: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/19.jpg)
19
2. NS-2 의 802_11Ext 클래스
![Page 20: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/20.jpg)
기존 ns2 의 802.11 구현 문제점• Wrong collision handling
• No preamble and PLCP header modeling
• No cumulative SINR implementation
• Wrong backoff handling
• Misusage of the network allocation vector (e.g. EIFS)
• Incomplete support for capture
![Page 21: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/21.jpg)
802.11a, b, g 설정 상의 문제
![Page 22: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/22.jpg)
802.11a 의 성능 그래프(basic rate = 6Mbps, data rate = 54Mbps)
![Page 23: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/23.jpg)
More accurate IEEE 802.11 implementation in NS2
MSWiM’07, October 22–26, 2007, Chania, Crete Island,
Greece.
![Page 24: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/24.jpg)
802.11 transmission and reception (1/3)
• Modulation and coding rate
![Page 25: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/25.jpg)
802.11 transmission and reception (1/3)
• PHY layer frame structure
![Page 26: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/26.jpg)
802.11 transmission and reception (1/3)
• Frame reception process– Preamble– PLCP header– Frame
• In transmission– Not allowing to overhear
• In reception– Collision– Capture effect
Preamble Frame body
![Page 27: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/27.jpg)
Revised Architecture
![Page 28: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/28.jpg)
PHY modeling (1/2)
• Power monitor– All information on received signals is processed and
managed in this module.
• PHY state manager
![Page 29: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/29.jpg)
PHY modeling (1/2)
• Frame drop reasons
![Page 30: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/30.jpg)
MAC modeling (1/6)
• Transmission module– The interface to the PHY – RTS, DATA from transmission coordination– CTS, ACK from reception coordination– TX_IDLE and TXing states
![Page 31: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/31.jpg)
MAC modeling (2/6)
• Reception module– Receiving frame– Address filtering– NAV update of channel state manager– RX_IDLE and Rxing states
![Page 32: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/32.jpg)
MAC modeling (3/6)
• Channel state manager
![Page 33: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/33.jpg)
MAC modeling (4/6)
• Backoff manager
![Page 34: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/34.jpg)
MAC modeling (5/6)
• Transmission coordination module
![Page 35: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/35.jpg)
MAC modeling (6/6)
• Reception coordination module
![Page 36: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/36.jpg)
Bug fix for modulation
36
![Page 37: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/37.jpg)
3. NS-2 의 IEEE 802.11 MAC 구현- MAC 프레임의 전송 및 수신 과정
37
![Page 38: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/38.jpg)
IEEE 802.11 in ns-2
• IEEE 802.11 기반의 프레임 송수신 과정– CSMA/CA 기법 , 지수적 Backoff 기법 , RTS/CTS,
재전송 기법 등
• Mac802_11Ext – ns-2 에서 IEEE 802.11 의 MAC 을 추사화한 클래스– mac-802_11Ext.h, mac-802_11Ext.cc, mac-timers.h,
mac-timers.cc
38
![Page 39: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/39.jpg)
802.11 프레임 전송과정• 기존의 구현
– 백오프 (Backoff) 과정 수행– 데이터를 전송하는 노드와 수신하는 노드간에 RTS/CTS
프레임을 교환– 데이터를 전송한 후에 일정 시간내에 ACK 프레임을
수신해야 함 . 만약 ACK 프레임을 수신하지 못하면 데이터를 재전송
• 기존의 구현과 유사하나 TXC 클래스를 통해 기존 백오프의 수행과정의 오류 수정
39
![Page 40: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/40.jpg)
802.11 프레임 전송과정• 상위 계층 (TCP, UDP) 에서 프레임의 전송을
요구하면 , Mac802_11Ext 의 recv() 함수 호출• recv() 함수
40
![Page 41: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/41.jpg)
802.11 프레임 전송과정• handleMsgFromUp() 함수
![Page 42: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/42.jpg)
802.11 프레임 전송과정• handleMsgFromUp() 함수
![Page 43: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/43.jpg)
802.11 프레임 전송과정• prepareMPDU() 함수
![Page 44: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/44.jpg)
802.11 프레임 전송과정• generateRTSFrame() 함수
![Page 45: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/45.jpg)
802.11 프레임 전송과정• generateRTSFrame() 함수
![Page 46: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/46.jpg)
802.11 프레임 전송과정• transmit() 함수
PHY 계층으로 전달
![Page 47: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/47.jpg)
802.11 프레임 전송과정• handleBKStart() 함수
![Page 48: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/48.jpg)
802.11 프레임 전송과정• handleBackoffTimer() 함수
![Page 49: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/49.jpg)
802.11 프레임 수신과정• 기존의 구현
– PHY 에서 구현되어야 할 기능들이 MAC 계층에 구현 전체 프레임 중 첫 비트가 목적지 단말에 도착했을 때 recv()
함수가 호출 전체 프레임이 도착하는 시간 동안 다른 프레임의 신호을
수신하는 경우• 이미 수신 중인 프레임과 충돌
프레임을 수신하는 시간 동안 프레임을 전송• 수신 프레임과 충돌하기 때문에 수신 프레임에 에러가 발생
• PHY 에서 프레임을 수신한 뒤 , MAC 의RXC::handleMsgFromBelow() 함수가 호출
![Page 50: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/50.jpg)
802.11 프레임 수신과정• handleMsgFromBelow() 함수
![Page 51: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/51.jpg)
802.11 프레임 수신과정• handleMsgFromBelow() 함수
![Page 52: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/52.jpg)
802.11 프레임 수신과정• handleACKIndication() 함수
![Page 53: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/53.jpg)
802.11 프레임 수신과정• handleCTSIndication() 함수
![Page 54: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/54.jpg)
802.11 프레임 수신과정• recvDATA() 함수
![Page 55: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/55.jpg)
4. IEEE 802.11 PHY 구현- Wireless PHY Ext 의 클래스 구조
55
![Page 56: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/56.jpg)
IEEE 802.11 기반 PHY 계층• 기존의 구현
– WirelessPhy 클래스 Error Model, Energy Model, Propagation Model 수신한 프레임에 확률에 기반한 비트 에러를 생성 전파 모델에 기반하여 수신 프레임의 시그널 세기에 결정
프레임의 수신 가능 여부를 판단
– WirelessChannel 클래스 프레임의 브로드캐스트를 처리 프레임의 전송 세기 , 전파 모델에 기반하여 전파의 도달 범위를
계산 노드의 위치정보를 이용하여 전송한 프레임을 수신할 이웃 노드을
선택
• wirelss-phyExt.cc
![Page 57: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/57.jpg)
• WirelessPhyExt 클래스 sendDown() 함수
![Page 58: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/58.jpg)
• WirelessPhyExt 클래스 sendDown() 함수
![Page 59: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/59.jpg)
• WirelessPhyExt 클래스 sendUp() 함수
![Page 60: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/60.jpg)
• WirelessPhyExt 클래스 sendUp() 함수
![Page 61: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/61.jpg)
• WirelessPhyExt 클래스 sendUp() 함수
![Page 62: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/62.jpg)
• WirelessPhyExt 클래스 sendUp() 함수
![Page 63: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/63.jpg)
• WirelessChannel 클래스의 sendUp() 함수void WirelessChannel::sendUp(Packet* p, Phy *tifp) { sendUp() 함수 Scheduler &s = Scheduler::instance(); Phy *rifp = ifhead_.lh_first; Node *tnode = tifp->node(); Node *rnode = 0; Packet *newp; double propdelay = 0.0; struct hdr_cmn *hdr = HDR_CMN(p);
프레임을 전송하는 노드프레임의 공통 헤더
… hdr->direction() = hdr_cmn::UP;
… 프레임의 진행 방향을 수신으로 설정
{ MobileNode *mtnode = (MobileNode *) tnode; MobileNode **affectedNodes; int numAffectedNodes = -1, i;
전송하는 노드이웃 노드 리스트를 저장할 배열이웃 노드 수
if(!sorted_) sortLists(); 모든 노드를 정렬 affectedNodes = getAffectedNodes(mtnode, distCST_+ 5, &numAffectedNodes); /* safety */
전송하는 노드와 전송 거리에 따른 이웃 노드 결정
for (i=0; i < numAffectedNodes; i++) { rnode = affectedNodes[i]; if(rnode == tnode) continue;
자신을 제외한 각 이웃노드 마다
newp = p->copy(); 전송할 프레임을 복사 propdelay = get_pdelay(tnode, rnode); 전송 지연 시간 계산 rifp = (rnode->ifhead()).lh_first; for(; rifp; rifp = rifp->nextnode()){ s.schedule(rifp, newp, propdelay); }
각 노드의 다수의 무선 인터페이스가 존재하면 , 각 인터페이스마다Propagation delay 시 뮬 레 이 션 한 후 프레임 전송
} delete [] affectedNodes; 메모리 해제 } Packet::free(p);}
![Page 64: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/64.jpg)
Code analysis #1
![Page 65: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/65.jpg)
Code analysis #2
![Page 66: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/66.jpg)
4. 시뮬레이션 예제 데모
66
![Page 67: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/67.jpg)
5. 802_11Ext 을 기반으로 directional antenna 구현 및 확장 예제
67
![Page 68: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/68.jpg)
Code analysis #1
![Page 69: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/69.jpg)
Code analysis #2
![Page 70: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/70.jpg)
지향성안테나 구현 및 테스트• 구현코드
– antenna.{h, cc}– directable-antenna.{h, cc}– twoground.{h, cc}
![Page 71: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/71.jpg)
antenna.{h, cc}
![Page 72: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/72.jpg)
tworayground.{h, cc}
![Page 73: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/73.jpg)
tworayground.{h, cc}
![Page 74: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/74.jpg)
74
![Page 75: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/75.jpg)
Test script
![Page 76: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/76.jpg)
Simulation results (wd=15)
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+00
1.00E+07
2.00E+07
3.00E+07
4.00E+07
5.00E+07
6.00E+07
7.00E+07
180
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+005.00E+031.00E+041.50E+042.00E+042.50E+04
150
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+00
5.00E-06
1.00E-05
1.50E-05
120
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+00
5.00E-01
1.00E+00
90
![Page 77: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/77.jpg)
Simulation results (wd=60)
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+005.00E+051.00E+061.50E+062.00E+062.50E+063.00E+063.50E+064.00E+06
180
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+00
5.00E+05
1.00E+06
1.50E+06
2.00E+06
2.50E+06
150
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+001.00E+052.00E+053.00E+054.00E+055.00E+056.00E+05
130
55 61 67 73 79 85 91 97 104
110
116
122
128
134
140
0.00E+00
4.00E+04
8.00E+04
90
![Page 78: NS2단기강좌-2011-10-10 (1).pptx](https://reader036.vdocuments.pub/reader036/viewer/2022081412/545279e0af79591d308b4f72/html5/thumbnails/78.jpg)
Q & A
78