Why would a STA that supports 802.11k Radio Measurement send a Neighbor Request to an AP?

The IEEE 802.11k amendment, "Radio Resource Measurement," is designed to improve traffic distribution within a wireless network. A key feature is the Neighbor Report mechanism. A client station (STA) sends a Neighbor Request frame to its currently associated Access Point (AP) to ask for information about nearby APs that are suitable candidates for roaming. The AP responds with a Neighbor Report frame containing a list of these APs and their characteristics (e.g., channel, BSSID). This process allows the STA to build a comprehensive view of potential roaming targets without having to perform disruptive and time-consuming off-channel scanning, leading to faster and more efficient roaming decisions.

A. The Neighbor Request's specific purpose is to discover candidate APs for roaming, not to identify general interference sources.

B. Informing an AP of an intent to roam is a function associated with other amendments, such as 802.11r (Fast BSS Transition), not the 802.11k Neighbor Request.

D. The Neighbor Request is for a list of neighboring APs, not neighboring STAs. Protection mechanisms are determined by other factors, such as channel contention.

1. IEEE Std 802.11™-2020 (Revision of IEEE Std 802.11-2016).

Section 11.11.10, "Neighbor Report element": This section details the contents of the report, stating, "The Neighbor Report element contains information on neighbor APs... that are candidates for a BSS transition." This confirms the purpose is to provide a list of roaming candidate APs.

Section 9.6.16, "Neighbor Report Action frame format": This section defines the frame used for the request and response, solidifying its role in the AP discovery process for roaming.

2. Cisco, "Radio Resource Management under Unified Wireless Networks," White Paper.

Section: "802.11k," Page 6: The document explains, "With 802.11k, an AP can respond to a client's request for a neighbor list... The client can then use this neighbor list to have a pre-emptive idea of good roam candidates." This directly supports the function described in the correct answer.

3. Aruba Networks, "802.11k, 802.11v, and 802.11r," Technical Note.

Section: "802.11k," Page 2: "The 802.11k protocol provides a mechanism for APs and clients to dynamically measure the available radio resources. APs can provide clients with a list of neighboring APs that are candidates for roaming." This explicitly states the purpose of the Neighbor Request/Report exchange.