Environments for Mobile and Wireless Communications (C1-C3)
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Environments for Mobile and Wireless Communications (C1-C3)
Course | UNIK4700, UNIK9700 |
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Title | Frequency Ranges and Propagation Models for Communications |
Lecture date | 2014/09/26 0915-1145 |
presented | by Raul, Yun Ai |
Objective | Present the first assignments:
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Learning outcomes | * get feedback on how to structure a presentation
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Pensum (read before) | |
References (further info) | |
Keywords | Frequency, Propagation Models, Wifi, Mobile Systems |
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Presentations
Related topics
⌘Propagation scenario (ITU-R)
Radio coverage [km2] | Distance [km] | speed of mobile [km/h] | type of cell | |
Indoor office environment | 0.01 | 0.1 | 3 | picocell in open space environment |
Pedestrian mode | 4 | 2 | 3 | Microcell |
Vehicle | 150 | 13 | 120 | Macrocell |
- see page 31 of ETSI TR 101 120 report for test environments
- impact on walls?
⌘Propagation models
- Environments (indoor, outdoor to indoor, vehicular)
- outside (Lee, Okumura, Hata, Unik/COST231-Hata, Unik/COST231-Walfish-Ikegami)
- inside (One-slope, multiwall, linear attenuation)
References:
- T.K. Sarkar, J. Zhong, K. Kyungjung, A. Medouri, M. Salazar-Palma, "A survey of various propagation models for mobile communications", IEEE Ant. Prop. Magazine, 2003, 45(3) 51-82
- M Hata, "Empirical formula for propagationloss in land mobile radio service". IEEE Trans Vehicular Technology, 1980, vol 29, pp 317-325
- F Ikekami, S Yoshida, T Takeuchi, M Umehira, "Propagation factors controlling mean field strength on urban streets", IEEE Trans Ant. Prop., 1984, 32(8), 822-829
- T.S. Rappaport, S. Sandhu, "Rdaio Wave propagation for Emergin Wireless Personal Communication Systems", IEEE Ant. Prop. Magazine, 1994, 36(5), 14-23
we will focus only on ETSI models: statistical models to generate path losses and time delay structures for paths in each test environment.
(Source: Cost259, page 80ff, and ETSI TR 101 120)
⌘ Mobile Propagation References
References:
- Eurescom P921: UMTS radio access, http://www.eurescom.de D2-UMTS radio access
- ETSI / ITU propagation channels (Vehicular A/B, Outdoor to indoor A/B)
⌘ C2-Outdoor communications
⌘Measurements in rural farmland
- Typical IR from Farm_1, 1718 MHz. Total received power was –84 dBm, 20 dB above GSM sensitivity level
(Source:R Rækken, G. Løvnes, Telektronikk)
These questions are valid for all of the following impulse responses
- from delay, calculate reflection factor and free space attenuation
- describe characteristics of reflection
⌘ Measurements in rural farmland
- Typical IR from Farm_2, 953MHz. Total received power was <93dBm
(Source:R Rækken, G. Løvnes, Telektronikk)
⌘Measurements in cities
- Typical IR from City street measurements, 1950 MHz, Oslo. Output power 25 dBm ( in mW?). Omnidirectional -Dipoles used as transmit and receive antennas.
(Source:R Rækken, G. Løvnes, Telektronikk)
why almost equal distribution? What effect?
⌘ETSI urban pedestrian
- Outdoor to indoor and pedestrian test environment, based on Non LOS (NLOS)
- Base stations with low antenna height are located outdoors, pedestrian users are located on streets and inside buildings and residences
- TX power is 14 dBm, f = 2000 MHz and r is distance in m
- Assumes average building penetration loss of 12 dB
- Path loss model: [dB]
⌘COST Walfish-Ikegami Model
- taking into consideration propagation over roof tops
- assumes antennas below roof top
- Path loss model: [dB]
⌘Alternative Street Microcell Path-loss
- Outdoor propagation, consists of "adding of paths"
- c is angle of street crossing. c = 0.5 for 90 deg crossing
- k_0 = 1 and d_0 = 0
- Path loss model: [dB]
- illusory distance with
⌘ETSI vehicular
- larger cells (typical few km)
- TX power 24 dBm for mobile phone, transmit antenna height over roof top (typical 15 m), distance r in km, f = 2000 MHz
- Path loss model: [dB]
⌘Forest, 961 MHz measurements
- slightly hilly terrain
(Source:István Z.Kovács,Ph.D.Lecture,CPK, September6, 2002;p.27/45 )
⌘Forest, 1890 MHz measurements
- slightly hilly terrain
(Source:István Z.Kovács,Ph.D.Lecture,CPK, September6, 2002, p.27/45)
⌘Examples
establish table (L free space, pedestrial, outdoor, ...) with typical values for 900 and 2000 MHz and distances from 100 to 3000 m
⌘ETSI Indoor Office test environment
- derived from COST 231
- r is transmitter-receiver distance in m; n is number of floors in the path
- path loss L should always be more than free space loss. Log-normal shadow fading standard deviation of 12 dB
- Path loss model: [dB]
⌘Modelling approach - indoor
Typical ETSI parameters: 8 kbps, BER < 10'^-3^', 20 ms delay, 50 % activity
(Source:Radio Wave Propagation for Telecommunication, Springer, and ETSI TR 101 112 V3.2.0 (1998-04))
Next lecture D1 Proximity Systems such as NFC, RFID