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Antennes et accessoires
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Différentes formes d’antennes pour différents besoins Largeur de faisceau PoE Accessoires Connectique
Le “Doughnut” Penser à la couverture radio comme à un ballon de volume fixe mais que l’on peut étirer La puissance d’émission a un effet direct sur le volume du ballon
Antennes omni-directionnelles Les plus communes Dipole irradiant identiquement dans toutes les directions Usage : Couverture horizontale dans toutes les directions “Point-to-multipoint connection”
Antennes semi-directionnelles Directionnel Usage : Liaisons de type pont de courtes et moyennes distances “Point-topoint connection”
Antennes directionnelles Hautement directionnel Usage : Liaisons de type longue distances “Point-to-point connection”
Largeur de faisceau-Beamwidth Type Beamwidth Beamwidth d’antenne horiz.(°) vert.(°)
Omni
360
780
Patch/ Panel
30180
690
Yagi
3078
1464
Parabole 425
421
Free Space Path Loss Path Loss Pertes par dispersions La puissance du signal diminue de manière inversement proportionnelle à la distance parcourue et à la longueur d’onde Règle des 6dB (à 2,4 Ghz) +6dB en PIRE correspond à doubler la distance.
Distance (m)
100 200 500 1000
Perte (dB) ~80 ~86 ~94 ~100
Montage PoE - Power over Ethernet Montages en : Plafond – ceiling Mat – mast Patch
PoE - Power over Ethernet Ou “the LAN outlet becomes a universal power jack…“
Terminology June 2003: the IEEE 802.3af 2003 PoE standard was formally ratified, establishing uniform requirements for managing and distributing 48 V dc power over the LAN. That standard defines the protocols for the: power devices (PDs) include, factory automation equipment, WLAccessPoints, RF ID scanners… power-sourcing equipment (PSE), the Ethernet hubs and switches, to transmit power over CAT 5 and other cabling to the PDs, such as the VoIP phones and other network peripherals
RJ-45 connections used for Power over Ethernet
The PSE encompasses two categories of equipment: midspan and endspan devices.
A midspan device is a stand-alone unit that adds the PoE capability to existing networking equipment. The unit is inserted into the LAN between the Ethernet switch and the peripherals. However, a midspan device requires additional cabling, takes up extra space, and adds cost to the system. These problems are lessened by incorporating PoE functionality directly into the Ethernet switches. Such pieces of equipment are called endspan devices.
Power consumption classes
Compatibility issues The two main legacy systems: Cisco and PowerDsine.
Cisco Systems has been shipping its Power over Ethernet solution since 2000 The Cisco Prestandard Power over Ethernet solution uses a different discovery and management scheme of the PDs. Issue: inrush current level needed by PD identified by some PSE as a fault shut down power to the PD Existing 802.3af-compliant PSE solutions can be adapted to work with Cisco PDs
Power gadgets Amplificateur
Atténuateur
Power gadgets Parafoudre
Splitter
Connexions & Cables Respecter l’impédance ! Différents types de connecteurs Cable == pertes (abaques) Perte : 0,222 dB par mètre Masse : 0.10 kg/m Impédance : 50 Ohms Diamètre externe : 10.29 mm
