Chapter 7 Politeknik Telkom 2008

Device of Wireless Network PCMCIA Radio device

Vendor D-Link

Vendor 3com

Vendor Belkin Linksys Broadcom

PoE Power over Ethernet (PoE) is mekanism to supply power through network device, ex : switch, hub

PoE

Class of power

Device vs Power Requirement

Class of power

Type of Antenna Omnidirectional Directional / Sectoral

Omnidirectional Antenna

Sectoral Antenna

Lobe Lobe is radiation pattern in an antenna Lobe for omnidirectional antenna Horisontal lobe Vertical lobe

Lobe sectoral / directional horisontal vertical Directional

Angle

Angle Parameter : Hb = height of base station (meter) Hr = height of receiver (meter) A = angle of antenna (degree) Distance (km)

Exercise 1 A base station has height 30 meter from the ground and receiver has height 10 meter. Distance between base station to receiver are 3 km. Find angle of antenna in the base station ?

Anwer exercise 1 A = tan-1 [(Hb-Hr)/(distancex5280)] = tan-1 [(30-10)/(3x5280] = tan-1 [20/15840] = 0,072°

Radius

Radius Parameter : H = height of antenna (meter) A = tilt angle of antenna BW = width of beam

Exercise 2 A base station has height 30 meter, with beamwitdh = 10°, A=0,2° Find : Inner radius distance ? Outer radius distance ?

Answer exercise 2 = [30/Tan(0,2+(10/2))]/5280 = [30/Tan(5,2)]/5280 = [30/0,09]/5280 = 0,063 km = 63 meter

Answer exercise 2 = [30/Tan(0,2+(10/2))]/5280 = [30/Tan(-4,8)]/5280 = [30/0,09]/5280 = 0,063 km = 63 meter

Attenuation Loss/gain vs power (Loss) -3 dB = - ½ x power (Gain) +3 dB = 2 x power (double power) (gain) +6 dB = 4 x power (increasing power 4x)

Attenuation type obstacle vs loss Additional Loss (dB) Obstruction Open space Window (nonmetallic tint) 3 Window (metallic tint) 5 – 8 Light wall (drywall) Medium wall (wood) 10 Heavy wall (15 cm solid core) 15 – 20 Very heavy wall (30 cm solid core) 20 – 25 Floor/ceiling (solid core) Floor/ceiling (heavy solid core)

Attenuation

Exercise 3 Hb =100 meter, hm=5 meter, and lamda=1.116 meter, distance between transmitter and receiver 5000 meter. Assume gain antenna 8 dB and 0 dB for Access Point and receiver. Find : A. Free space attenuation B. Reflection attenuation

Answer exercise 3 Gb  8 dB = 10 log Gb Gb = 6,3 Gm  0 dB = 10 log Gm

Answer exercise 3