Cambium Networks equipment dominates Pakistani WISP backhaul deployments. The combination of licensing-free ISM band operation for most products, proven outdoor performance in the heat and weather conditions common to Pakistan's climate zones, and a mature local distributor and support network makes Cambium the practical default for operators building wireless backhaul from a tower or rooftop hub to subscriber sites or distribution points.

Effective Cambium backhaul planning means choosing the right product family for each link type, calculating link budgets before installation, and planning frequency use across a site to avoid self-interference. The hardware is reliable, but a poorly planned deployment on reliable hardware performs poorly.

Product Family Selection

Cambium's product portfolio has three families relevant to WISP backhaul.

PTP (Point-to-Point) links, primarily the PTP 550 and PTP 670 series, are designed for high-capacity point-to-point backhaul between fixed sites. The PTP 550 operates in the 5 GHz ISM band and delivers up to 1.3 Gbps aggregate in a 2x2 MIMO configuration. The PTP 670 operates in licensed bands (6-11 GHz) and delivers higher capacity with interference immunity from licensed spectrum. For WISP operators connecting tower sites to hub aggregation points where the link capacity requirement exceeds 300-400 Mbps and interference is a concern, the PTP 550 is the ISM band choice and PTP 670 is the licensed band choice.

ePMP is a platform designed for point-to-multipoint subscriber access and point-to-point backhaul in the same ISM bands. The ePMP Force series are directional point-to-point links. The ePMP 3000 series access points support both subscriber access and backhaul use. For WISPs building a mixed network where the same platform handles both subscriber connectivity and site interconnects at capacity below 200 Mbps per link, ePMP provides platform consistency and operational simplicity.

PMP (Point-to-MultiPoint) products, specifically the cnWave 60 GHz platform and the 450 series, handle subscriber access at shorter ranges. The 60 GHz cnWave delivers multi-gigabit capacity over distances under 1-2 km in clear line-of-sight conditions, appropriate for dense urban FTTH-replacement deployments. The 450 series operates in licensed bands and provides predictable performance where ISM interference is severe.

Link Budget Calculation

A link budget calculation determines whether a proposed wireless link will meet your minimum signal level requirements under worst-case conditions. The calculation accounts for: transmit power, antenna gain at both ends, free-space path loss at the operating frequency and distance, and any additional losses from obstructions, atmospheric absorption, or rain fade.

Free-space path loss in dB is calculated as: 20 x log10(distance in km) + 20 x log10(frequency in MHz) + 32.4. For a 5 km link at 5.8 GHz, free-space path loss is approximately 120 dB.

A Cambium PTP 550 with 25 dBi antennas at both ends has a total antenna gain of 50 dBi. At 24 dBm transmit power, the effective isotropic radiated power is 74 dBm. Subtract path loss: 74 - 120 = -46 dBm received signal level. The PTP 550's receive sensitivity at the highest modulation (1024-QAM 5/6 MIMO) is approximately -66 dBm. The link margin is 20 dB, which is generally adequate for a 5 km clear line-of-sight link.

Cambium's LinkPlanner tool automates this calculation and integrates terrain data, which is the correct approach for anything beyond a simple line-of-sight link over flat terrain.

Frequency Planning for Multi-Site Deployments

ISM band frequency planning is the most commonly neglected aspect of WISP backhaul design and the most common cause of performance problems in mature networks. As the number of Cambium links in an area grows, the potential for self-interference between links grows with it. Without frequency planning, links on the same channel within radio range of each other create interference that limits effective throughput even when individual links show good signal levels.

The 5 GHz ISM band (5.170-5.835 GHz in Pakistan, subject to FAB regulations) provides approximately 19 non-overlapping 40 MHz channels or 9 non-overlapping 80 MHz channels. With careful frequency assignment, a tower site with four backhaul links can avoid self-interference entirely by assigning each link to a different channel with sufficient separation.

Frequency planning principles for Cambium deployments: assign different channels to links that share a common endpoint (tower site), separate links that are within approximately 30 km of each other on the same or adjacent channels, use the horizontal and vertical polarization options in Cambium PTP gear to provide additional isolation between co-located links where channel separation alone is insufficient.

cnMaestro for Centralized Management

Cambium's cnMaestro platform provides centralized monitoring and management for all Cambium equipment across a WISP deployment. For operators with more than 10-15 Cambium devices, managing them individually is operationally unsustainable. cnMaestro provides fleet-wide firmware updates, configuration templates, performance monitoring, and alarm management from a single interface.

cnMaestro is available as a cloud-hosted service (Cambium-hosted) or as an on-premises VM. For operators with reliable internet connectivity at the NOC, the cloud-hosted option requires no server infrastructure. For operators who prefer on-premises management, the VM runs on standard hypervisor infrastructure.

Integrate cnMaestro alarms with your NOC alerting infrastructure. cnMaestro supports alarm forwarding via webhook or SNMP trap, which feeds into Zabbix, Grafana, or whatever NMS platform your NOC uses. This gives your NOC team visibility into wireless link status alongside the wired infrastructure in a single pane.

For WISP network design that covers the full backhaul topology from hub through distribution to subscriber access, Network Design & Optimization covers Cambium deployment design alongside the routing and aggregation architecture. For NOC monitoring setup that integrates Cambium infrastructure alongside MikroTik and other platforms, NOC Enablement & Monitoring covers the unified monitoring stack design.