Support Our strategy Our goal is to remain the leading mobile satellite services provider — by developing our new Ka-band Global Xpress network and continuing to grow our core L-band business.
Ka-band is changing the face of satellite communications. Enabled by satellites having significantly higher capacity, Ka-band is delivering on its promise of low cost highly efficient communications.
Sample HTS coverage area. Ka-band used to deliver satellite broadband to home users and enterprises, the applications for Ka-band also extend into the maritime, aerospace, and defense sectors.
Widely referred to as third-generation broadband, or High-Throughput Satellite HTSthese systems are capable of delivering more than Gbps of data and servicing over one million users.
This is 10 to times the capacity of traditional wide coverage area systems. This is a significant increase in capacity; the primary motivator for HTS is to provide more bandwidth at a lower price per bit. What is different about these Ka-band systems?
First, the contiguous Ka-band spectrum reserved for satellite services is significantly wider than it is for Ku- or L-band. This provides larger bandwidths and inherently higher data rates. Additionally, Ka-band HTS are typically designed with payloads that have many narrow spot beams and high frequency reuse, as compared to the wider coverage areas and low frequency reuse of Ku-band payloads.
The Need For Capacity Management Whether you are a satellite operator, service provider, or network operator, you know that the satellite resource is your largest expenditure and that the ability to maximize performance and utilization of that asset is the key to a profitable venture.
To accomplish this task, you must dynamically manage your satellite resources initially and as capacity increases. Ka-band systems bring larger bandwidths, more spot beams, higher throughputs, and new gateway and payload designs.
This is demanding new and innovative capacity management and planning toolsets that address the complex issues associated with Ka-band and high capacity systems.
The most significant weather effect concerning Ka-band is rain, with the largest attenuations occurring during relatively short periods of intense rainfall up to 30 dB, in some cases. To compensate for weather effects, Ka-band systems are designed to mitigate deep rain fade.
Generally, the overall system is designed such that the forward link performance is dominated by the terminal downlink, while the return link performance is dominated by the terminal uplink.
The idea here is that the gateways can be designed for operation at specific locations, whereas terminals are required to operate where needed. The result is a gateway segment that provides a highly available feeder link.
Techniques used to accomplish this including planning the gateway locations in dry areas, using redundant gateways to add site diversity, implementing uplink power control, and using transponder automatic level control ALC when practical. Accurately modeling Ka-band propagation impairments and rain fade mitigation techniques are essential to planning capacity and designing robust satellite links.
As more Ka-band systems come into operation, more experience and knowledge regarding the frequency is being acquired and studied. This is leading to revised propagation models, updated climatic data, and new system designs for rain fade mitigation. Consequently, the propagation models are changing—much more rapidly than in the past.
To remain effective, capacity planning tools need to be flexible in accommodating updated models and data files. To assist, SED offers pluggable software modules that implement the latest ITU-R propagation models and software libraries for modeling site diversity improvement, uplink power control, and transponder ALC.
Interference Considerations Ka-band Comparatively, Ku-band is much more widely used with almost all orbital slots occupied. With Ku- interference to adjacent satellites is often the limiting factor in terms of terminal size for the return link.
Ka-band has a better interference environment and its use in practice is limited to small terminals Figure 2. Additionally, the Ka-band spectrum allocated to satellite communications is not currently allocated to any terrestrial services on a primary basis.
Interference with adjacent satellites and terrestrial services can be thought of as external interference, and although important to consider for Ka-band, is not as dominating as it is for Ku-band.
What is more important for Ka-band is the consideration of internal system interference. HTS Ka-band systems employ high-gain narrow spot beams and large amounts of frequency reuse.
Adjacent beams use different frequencies, polarizations, or combination thereof. The number and size of the spot beams vary between systems, but generally the spots cover several hundred kilometers, with the larger systems having upwards of spot beams.
Depending on the number of gateways deployed and the amount of bandwidth available in each beam 50 to MHzfrequency reuse can be up to 20 times. Depending on the satellite antenna technology used and corresponding transponder levels, the isolation between beams reusing the same frequency can vary between 20 and 30 dB and, in some cases, be less than 20 dB.
Understanding the impacts of frequency reuse and beam power allotments are critical to operating a multi-spot beam system. SED offers software to analyze and visualize beam coverage patterns and beam-to-beam isolation for multi-spot beam systems of varying sizes from a few beams to hundreds beams.
Co-polarization, cross-polarization, and combined modes are supported. Coverage analysis functionality displays contours either relative to beam-peak or to edge-of-beam. Isolation values can be displayed as heat maps with a configurable resolution and color gradient. Given a carrier load, the software will compute the level of induced and incurred interference in beams using overlapping frequency.
Using these tools, the carrier to interference noise can be effectively managed by trading off interference levels with beam loading.Case study: Implementing business continuity in the upstream and midstream energy sector (petrochemicals and refineries) The business continuity plan development methodology applied was based on BS , as the company wanted to lead the way in the region in the adoption of the standard.
SED Systems provides software systems, tools, and services to assist satellite operators, service providers, and network operators to efficiently and effectively plan and manage the capacity and services of their Ka-band satellite systems.
For business jet travelers interested in the best global primary and backup connectivity service, Viasat's Ku-band service, available via GoDirect, includes global Ku . For business jet travelers interested in the best global primary and backup connectivity service, Viasat's Ku-band service, available via GoDirect, includes global Ku-band data on all Ka-band plans 40 GB and larger–at no additional service cost.
Thales reveals plan for global, high-capacity Ka inflight connectivity. Thales forged an arrangement that sees SES leasing Ka-band capacity on in-orbit Hughes satellites to support Thales connectivity on aircraft in North America.
And when we look at the presence and the volume of business in North America, we could imagine for Asia. Sizing the service plan for one customer is one aspect of the CST. A second and equally important aspect is combining multiple service plans into a group service plan to maximize the usage of shared capacity.
Intermodulation Considerations @ Ka-band Russ is the Business Manager of Satellite Communications Planning and Management .