Home » Cisco » 300-360 » Which type of antenna do you use with the RAP for backhaul connectivity?
You are designing an outdoor mesh network to cover several sports fields. The core of the network is located in a building at the entrance of a sports complex.
Which type of antenna do you use with the RAP for backhaul connectivity?
A. a 5 GHz, 14-dBi patch antenna
B. a 5 GHz, 8-dBi omnidirectional antenna
C. a 2.4 GHz, 14-dBi omnidirectional antenna
D. a 2.4 GHz, 8-dBi patch antenna
Correct Answer: B
Explanation/Reference:
Explanation:
The AP1524PS includes three radios: a 2.4-GHz, a 5.8-GHz, and a 4.9-GHz radio. The 2.4-GHz radio is for client access (non-public safety traffic) and the 4.9-GHz radio is for public safety client access traffic only. The 5.8-GHz radio can be used as the backhaul for both public safety and non-public safety traffic.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/7-6/configurationguide/b_cg76/b_cg76_chapter_010000001 .html
Omni to cover a large, flat area like several sports fields.
Patch if your RAP is up high and your MAPs are low.
Determining a Line of Sight
When you determine the suitability of a successful link, you must define how far the link is expected to transmit and at what radio data rate. Very close links, one kilometer or less, are fairly easy to achieve assuming there is a clear line of sight (LOS)–a path with no obstructions.
Because mesh radio waves have very high frequency in the 5-GHz band, the radio wavelength is small; therefore, the radio waves do not travel as far as radio waves on lower frequencies, given the same amount of power. This higher frequency range makes the mesh ideal for unlicensed use because the radio waves do not travel far unless a high-gain antenna is used to tightly focus the radio waves in a given direction.
This high-gain antenna configuration is recommended only for connecting a RAP to the MAP. To optimize mesh behavior, omnidirectional antennas are used because mesh links are limited to one mile (1.6 km). The curvature of the earth does not impact line-of-sight calculations because the curvature of the earth changes every six miles (9.6 km). https://www.cisco.com/c/en/us/td/docs/wireless/technology/mesh/7-3/design/guide/Mesh/Mesh_chapter_0100.html
Omni is better, in order to establish backup backhaul links to other MAP (HA)
Omni for backhaul? I would say patch but A has a dBi that is not accurate for patch antenna.