# Wireless LAN 802.11 Service Sets
**URL:** https://forum.networklessons.com/t/wireless-lan-802-11-service-sets/8799
**Category:** Lessons Discussion
**Created:** [November 8, 2019, 2:59pm UTC](https://forum.networklessons.com/t/wireless-lan-802-11-service-sets/8799 "2019-11-08T14:59:42Z")
**Posts on this page:** 1
**Showing post:** 7
### Author:  [@michael3.chung](https://forum.networklessons.com/u/michael3.chung)
#### Post date: [May 30, 2020, 7:59am UTC](https://forum.networklessons.com/t/wireless-lan-802-11-service-sets/8799/7 "2020-05-30T07:59:43Z")
Hi,
Could you please answer the following questions ?
1. How dose an AP is considered by upper(upstream) network? Is it a switch/bridge(L2) or router(L3)?
q1. Case 1(home): AP is directly connected to an ISP
q2. Case 2(soho, enterprise) : AP is connected to a (access)switch of hierarchical swiched network.
q2.1 How dose an AP is considered by the switch ?
q2.2 The link between AP and swich should be a trunk ?
q2.3 AP participates in Spanning tree protocol ?
2. AP repeater mode- 50% throughput reduction
In your lesson \, you say “Since wireless is half-duplex, adding a repeater will reduce your available throughput by about 50%.
To work around this, some repeaters have two or more radios. They receive on one channel (same as the AP) and retransmit on another”
q3. Why 50% throughput reduction ?
3. Repeater mode operation.
q4. I think repeater wireless should be full duplex(Normal WLAN device is half duplex). It listens from AP and talks to STAs simultaneously or vice versa
q5. If so, How Repeater knows the timing for downstream(AP to STAs) or upstream(STAs to AP)?
q6. Reaper mode also does CSMA/CA ?
Thanks
Michael
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