Cisco Certified Support Technician (CCST) NetworkingNetwork AccessHard
A network technician is troubleshooting a slow wireless connection in a dense office environment. Many users report intermittent disconnections and low throughput, even when close to an access point (AP). A site survey reveals a high number of APs operating on overlapping channels within the 2.4 GHz band. Which term best describes this issue?
- ABeamforming
- BRogue AP
- CCo-channel interference
- DBand steering
Show answer & explanationAnswer & explanation
Correct answer: C. Co-channel interference
Co-channel interference occurs when multiple access points or wireless devices operate on the same frequency channel within the same area, leading to contention for the medium, increased retransmissions, and reduced performance for all devices sharing that channel.
Why the other options are wrong
- A. Beamforming is a technique to direct wireless signals towards a client for better performance, not a cause of interference from overlapping channels.
- B. A rogue AP is an unauthorized access point, which can cause security issues or interference, but the core problem here is specifically about multiple *authorized* APs using overlapping channels.
- D. Band steering guides dual-band clients to the 5 GHz band to relieve congestion on 2.4 GHz, but it's a solution, not the problem described.
Co-channel Interference
A type of interference in wireless networks where multiple access points or devices operate on the same frequency channel within the same geographic area, leading to signal collision, reduced throughput, and increased retransmissions.
- Occurs when APs share the same channel
- Common in dense 2.4 GHz environments
- Causes reduced throughput and increased latency
- Mitigated by proper channel planning (non-overlapping channels)
Memory trick: Co-channel collision, Adjacent channel overlap.