The Technixs staff have many years of experience in the design and installation of major digital microwave radio systems with capacities of up to multiple channels of 155 Mb/s.   We have carried out design work for asynchronous and SONET radio systems (155 Mb/s) and interconnected these to fiber optic systems to complete hybrid microwave/optical rings systems, which adds a couple of factors over the same design using a single media. For radio link paths at frequencies below 1 GHz, and operating with restricted bandwidths, strict line-of-sight (LOS) paths are not essential. Higher frequencies require line of sight and should be designed to minimize propagation problems that affect microwave paths such as reflections, fading, interference and dispersion.  It is possible to calculate the propagation loss from the terrain profile between the two ends of a link. We make use of an extensive topographical terrain database to prepare radio path profiles automatically. Once the path profile has been constructed from the terrain database.   The microwave direct ray, the diffracted ray and the first fresnel zone radius are plotted.   Values are calculated for the free space loss, the diffraction loss due to any obstruction, and an equivalent path length for each line-of-sight portion of the path. This can be used to calculate the expected short-term fading depths. Fading will also be caused by changes in the k-factor, which causes the apparent earth bulge to change as the refractive index profile.   The path analysis determines whether a path meets the clearance criteria above the terrain and any above ground obstructions. Clearance requirements are usually stated as a combination of a percentage of the first Fresnel zone radius and a K factor. For example, a common requirement is that 100% of the first Fresnel zone radius should be clear of all obstructions at a K factor of 4/3.   These calculations are also needed to select the proper size and type of antenna and select antenna height above ground level (AGL) on the supporting structure or tower.   The antenna centerline optimization analysis determines the minimum heights necessary to meet the clearance criteria. The antenna heights are chosen to minimize the possibility of reflective multipath. For a range of possible antenna heights at one end of a path, a trade-off analysis can be provided that shows the corresponding antenna heights that are required at the other end.

Technixs radio consulting services include: Computer coverage prediction Field surveying (GPS location, digital photos, tower measurements) Fixed link path profile and analysis (VHF/UHF and microwave) Radio path reliability/availability calculations Interference studies for systems with frequency re-use Interference tracing and elimination Site establishment (selection, acquisition, tower/mast, building etc) Solar, DC/battery, AC/diesel alternator power systems Grounding, bonding and shielding Alarm telemetry and remote data acquisition

Wireless LAN and WAN Projects Communications services includes telephone systems, cabling for telephone, data and video systems, security and access control systems, local area network (LAN) design, public address systems, as well as some unique features such as satellite TV receivers, and provision for remote monitoring.   In addition, we can prepare data networking strategy plans, and detailed documentation for provision or upgrading of computer networks (LANs and wide area links) for a large number of schools, campus outlying buildings and satellite locations. We also prepare cost estimates and a design brief for school internet access, web and email servers, video distribution systems, multimedia in the classroom projects.