Calculator
White theme • Responsive layoutUse this to estimate coordinated capacity for distributed access points across a construction site. Adjust assumptions for pilots, cooperation, and interference.
Example data table
These sample scenarios help compare coordinated deployments for a typical construction site. Values are illustrative and should be adjusted to match your equipment and layout.
| Scenario | B (MHz) | K | L | M | d (m) | Mode | Coop | Intf | Pilot/Coherence | Sum tput (Mbps) |
|---|---|---|---|---|---|---|---|---|---|---|
| Baseline site network | 40 | 12 | 10 | 4 | 120 | MR | 0.75 | 1.00 | 20/200 | ~ (calculator) |
| Dense AP grid near tower | 80 | 20 | 24 | 4 | 70 | ZF | 0.85 | 0.80 | 30/300 | ~ (calculator) |
| Harsh interference, long reach | 20 | 18 | 12 | 2 | 240 | MR | 0.60 | 1.80 | 25/200 | ~ (calculator) |
Formula used
This calculator provides a planning-level estimate of coordinated (cell-free) capacity using a simplified physical-layer model. It is suitable for early-stage design comparisons.
Noise and received power
- Noise power: N(dBm) = −174 + 10·log10(BHz) + NF
- Path loss: FSPL(f,d) plus an exponent term, shadowing planning loss (½σ), and a fade margin.
- Rx power: Prx(dBm) = Ptx(dBm) − PL(dB)
Capacity estimate
- Pilot efficiency: η = 1 − (τp·reuse)/τc (clamped).
- Effective SINR: array gain depends on APs, antennas, and coordination.
- Shannon rate: SE = η·log2(1+SINR), throughput T = B·SE.
How to use this calculator
- Enter the site scenario: bandwidth, frequency, number of users, and access points.
- Set propagation assumptions: average distance, path loss exponent, shadowing, and fade margin.
- Choose coordination settings: precoding mode, cooperation gain, and interference factor.
- Configure pilot parameters: coherence block, pilot length, and pilot reuse factor.
- Click Calculate. Results appear above the form.
- Download CSV for spreadsheets, or PDF for reporting.
Professional overview
Cell-free MIMO distributes many small access points (APs) across a jobsite and coordinates them so devices experience smoother coverage than a single tower. For construction, that means more reliable connectivity for safety wearables, machine telemetry, camera feeds, drones, and foreman tablets—especially when steel, concrete, and moving equipment create harsh multipath and shadowing.
This calculator supports early-stage planning by combining a link-budget style path-loss estimate with a coordination-aware SINR approximation and a Shannon-capacity throughput model. You can explore how bandwidth, AP density, antenna count, pilot overhead, and interference pressure trade off against each other. The “Cooperation gain” input lets you represent how well APs share channel information and scheduling decisions; higher values typically improve array gain and reduce coordination loss. The “Interference factor” captures how noisy the environment is, including adjacent networks, reflections, and imperfect isolation between zones.
Pilot and coherence settings are important for time-varying sites. Short coherence blocks (fast-changing channels from vehicles and cranes) increase estimation overhead because pilots consume a larger share of symbols. When pilot reuse is increased, contamination reduces, but the effective pilot cost rises. The tool reports pilot overhead so you can keep that burden in a reasonable range for your service level.
Example data (baseline): Use 40 MHz bandwidth at 3.5 GHz with 10 APs and 4 antennas per AP (40 total). Set 12 users, 120 m average distance, 23 dBm user power, and 7 dB noise figure. Choose MR, cooperation gain 0.75, interference factor 1.0, and pilots 20/200 (pilot/coherence). Click Calculate to see throughput, SINR, and the overhead impact immediately.
When interpreting results, focus on both sum throughput and per-user throughput. A high sum value with a low per-user value may indicate heavy user loading, pilot overhead, or strong interference. If pilot overhead exceeds about 15–20%, increase coherence assumptions only if the channel is truly stable, or reduce pilot length and reuse while monitoring SINR. If SINR is the limiting factor, add APs closer to work fronts, increase antennas per AP, or reduce the interference factor by improving channel planning and isolation. For ZF, ensure total antennas significantly exceed users; otherwise, MR can be more robust and predictable.
Use the results to compare deployment options, not as a substitute for a detailed radio survey. Once you narrow the design, validate assumptions with measurements, equipment specifications, and safety requirements. For reporting, export CSV for budgeting and PDF for stakeholder reviews.
FAQs
1) What does “cell-free” mean on a construction site?
It means multiple distributed APs jointly serve users, so devices are not tied to one “cell.” Coordination can reduce dead zones around obstructions and improve perceived stability while crews move.
2) Why are my results sensitive to average distance?
Distance drives path loss, which strongly affects received power and SINR. If users are frequently farther from APs than assumed, capacity can drop sharply, even when bandwidth is unchanged.
3) When should I pick ZF instead of MR?
ZF can help when the total antenna count is comfortably higher than the number of users and coordination is solid. It tends to suppress multiuser interference better than MR in dense-user conditions.
4) What is the interference factor representing?
It is a planning knob for background interference and modeling imperfections. Lower values represent cleaner spectrum and better isolation; higher values represent crowded spectrum, reflections, and tougher site conditions.
5) How do pilots and coherence affect throughput?
Pilots consume part of the coherence block, reducing data time. Shorter coherence or larger pilots increase overhead. Pilot reuse may reduce contamination but can raise effective pilot cost.
6) Is the output per-user throughput guaranteed for every device?
No. It is an average planning estimate. Real devices will vary due to location, blockage, scheduling, and hardware limits. Use margin, add APs, or reduce load to protect worst-case users.
7) How should I use CSV and PDF exports?
Use CSV to compare scenarios, run cost models, and share parameters with your design team. Use PDF to document assumptions and results for management, contractors, and compliance stakeholders.