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Overview: The following image illustrates how a well-planned wireless network design can seamlessly support up to 240 students in a university classroom.

I was prevously told that the Cisco Marlin, aka C9104, access point is nothing more than a C9130 housed in a NEMA rated antenna combo/enclosure. So… whats in the box? Back cover removed Silver AP Top Silver AP Bottom C9120 for Comparison Antenna Cables

Comming Soon The Cisco C9104 Stadium antenna offers a software-controlled beamwidth and beam steering feature that allows for some flexibility when installing this equipment. I recently performed some testing in our stadium and was surprised by the results.

What is MLO? Summary: Multi-Link Operation (MLO) allows Multi-Link Devices (MLDs) to maintain associations and simultaneously transmit data across multiple frequency bands, including 2.4-GHz, 5-GHz, and 6-GHz band. I recently set out to setup and test WiFi7 MLO in my lab environment using the Cisco C9800 and a C9178D and was a both surprised and dissapointed by my findings. It was a bit difficult to setup and I had some trouble following the AFC and SP configuration via Cisco’s documentation. There was some trial and error but was eventually successful. ...

It was absolutely wonderful to return to San Diego for Cisco Live this year, especially since it had been nearly 10 years since my last attendance. The experience was incredibly nostalgic and in my opinion is one of the best location for the conference. The weather was beautiful and the Gaslamp district has so much to offer. I am looking forward to the new WiFi7 CW9179F access point for large venues. It is 6 pounds lighter than the C9104 Marlin and has some really cool new features, including a back facing antenna. ...

My CWNE Journey Overview In this future post I will share my experience going through the CWNE Application process. Comming Soon - fingers crossed

What is Airtime Airtime is a critical metric in wireless design. It determines how much time a device occupies the channel to transmit or receive data. When multiple clients share the same radio, excessive airtime consumption leads to poor performance. This simplified calculation helps estimate how many AP radios are needed to support a given number of clients with specific application requirements. Key Assumptions Application throughput per client: 1 Mbps (e.g., basic web/email) 1 AP with 2 radios (2.4 & 5 GHz) Wi-Fi 6 (802.11ax) clients using typical MCS data rates Goal: keep total airtime per radio under 80% utilization Airtime Calculation Steps Determine Data Rate Based on MCS index, spatial streams (SS), modulation, and channel width. Data rate = MCS 5 + 2SS + 80 MHz ...

Overview This is a collection of important notes and information that I have collected over the years through my studies to act as a quick reference/refresher for myself. Important WiFi Metrics RSSI SNR MCS Data Rate Security Congestion Responsiveness Scans Selection Decisions Roaming Scans CAPWAP Ports 5246 – Control (DTLS) 5247 – Data RF Design Guidelines AP Spacing ~44–70 ft apart (~20% overlap) Avoid straight lines; stagger placement AP per Area Data only: 1 AP per 5,000 sq ft Voice: 1 AP per 3,000 sq ft High density: 1 AP per 11–120 sq ft Cisco: 1 AP per 2,000 sq ft Install Height 10–15 ft above ground Avoid HVAC, lights, beams AP Separation 10 ft between APs 3 ft from obstructions Design Tips Design at half power Model actual AP characteristics Signal Strength Targets Cell Edge (RSSI) -67 dBm for data -65 dBm for voice -75 dBm for location accuracy Roaming Target -70 dBm as roaming edge Voice latency: ≤100ms Client Tx Power Avg: 14 dBm (match AP when possible) SNR Minimum: >20 dB More critical than RSSI Channel Planning Unique Channels 2.4 GHz: 3 5 GHz: ~25 6 GHz PSC: 15 primary (every 4th) Interference Types CCI: Co-Channel Interference (same channel) ACI: Adjacent Channel Interference Channel Bonding Adds 3 dB noise OBSS = Overlapping bonded channels Performance Metrics Retries: <5% Packet Loss: <1% for voice <3% for data Latency: <150ms Jitter: <20ms Channel Utilization: Voice: <50% Video: <30% Carrier Sense Threshold: <-82 dBm Energy Detect: ~-62 to -72 dBm Power & Attenuation Same Channel Separation: >19 dB (e.g., -67 dBm edge, next AP < -86 dBm) Distance Rule: Every 6 dB drop ≈ 2× distance Attenuation Test: Place AP 12–16 ft from wall Measure both sides Client Handling Clients per AP: Typical: 30–50 High-density: 20–30 RTLS Requirements: Min 4 APs ≥3 APs at -62 dBm Outdoor Antennas Vertical Separation: 3–12 m (2.4/5 GHz) Horizontal Separation: 5 GHz: 7.5–15 m 2.4 GHz: 1–5 m Max Cable Length: 30 ft (10 m) Protocol & Behavior CAPWAP Heartbeat: 30s default SSID Limit: 3–4 recommended Management Frames: Lowest basic rate Multicast Frames: Highest basic rate Neighbor Ads: Sent at max AP Tx power 6 GHz Specifics Probing ...

Overview In this post I will outline some lessons learned about my journey designing for and deploying the Cisco C9104 Marlin access point in our stadium. Installation One of the many challenges of deploying wireless in a stadium is where to best mount the access points. There are many opinions on this matter with different preferences from wireless engineers depending on the design, layout, and mounting options. In our final design, we chose to use the catwalk to mount the access points facing the stands, but one thing I hadn’t previously considered was the catwalk’s weight capacity. The last thing I wanted weighing on my conscience,no pun intended, was the catwalk collapsing under the added load during an event. ...

First things first—it’s pronounced “FRAY-NEL Zone,” not “FRES-NEL Zone”. The term comes from physicist Augustin-Jean Fresnel, who made major contributions to the field of wave optics. When brainstorming a name for this blog, I wanted something that would resonate with the wireless community—something technical, but also memorable. Much like the Clear to Send podcast, I aimed for a name that symbolizes communication between two endpoints: the creator (me) and the reader (you). The Fresnel Zone felt like the perfect fit—an essential concept in wireless communication that also represents the space where our ideas and conversations intersect. ...