Where Telecoms & Energy Connect
More Bang for your BUC
Limited satellite network bandwidth has to cope with greater demands as the data, voice and video needs of remote oil and gas installations grow. However, as Vaughan O’Grady finds out, data compression and bandwidth optimization offer ways to make less satellite bandwidth do a lot more. So why are advances in data compression and bandwidth optimization so important to oil and gas companies in remote areas? Firstly, because of growing quantities of operational data ( including M2M, equipment monitoring and new applications in video), virtualised server applications, internet access, HDTV, SaaS and more. All can demand more bandwidth and yet, as Thomas Wurst, senior solutions engineer with Signalhorn, a provider of communications solutions employing satellite, terrestrial and wireless technologies, put it: “Remote rigs often have limited connectivity, low bandwidth, and high latency.” Which is why, according to Emerging Markets Communications ( EMC), a provider of hybrid global satellite and terrestrial communications, “Companies must control each user’s bandwidth utilization. Satellite connections must be optimized t o meet t he re quire ments of the application. A 10 Mbps satellite link must factor in the round- trip delay.”
More Bang for your Buck
A number of technologies and techniques can be used to help oil and gas companies cope with these demands and limitations. One such is echo cancellation, which, said EMC, “enables both directions of transmission to share the same satellite bandwidth capacity.” On legacy TDM networks, * Abis devices provide a good level of voice compression, allowing multiple E1s to be combined onto a single one. However, as end- to- end IP circuits arrive new techniques are being implemented. EMC noted: “Header compression and traffic shaping are standard options used in most of the VSAT NOC [ network operation centres].” TCP acceleration and optimization, HTML objects caching, JPEG transcoding and GZIP compression and byte caching all have applications. EMC also cites its own SpeedNet cloud- based ( and zero latency) web browser along with the HD Connect high definition application for video conferencing, which removes the need to buy dedicated capacity to integrate users on telepresence or videoconferencing systems. Signalhorn also cites application acceleration technologies and data compression based on technologies like zip, rar or other formats — as well as IP header compression, caching and proxy server technologies ( which reduce the response time to requests) and, of course, optimization of the TCP/ IP protocol. “The protocol parameters and transmission mechanisms — such as TCP window size and slow start — are modified by external devices or software to adapt to long latency connections,” Wurst explained. “This technology is also called protocol spoofing and is done at both ends of a connection to increase data throughput.” There is also de- duplication of data — eliminating information that will not be sent via the link. “The reconstruction at the other end is done based on data patterns that are already transmitted at an earlier stage,” Wurst said. On the VSAT technology side, he added, the capability for optimization depends on many factors such as the available space segment for the specific locations of the customer sites, frequency band, teleport capabilities and VSAT vendor technology. “Basically, the key mechanisms to achieve highly efficient space segment utilization are based on adaptive coding and modulation techniques or ‘ carrier- in- carrier’ solutions,” said Wurst.
Tore Morten Olsen is head of maritime satellite communications activities at Airbus Defence and Space, of which Marlink, an independent provider of services for the maritime industry, is a part. He commented that: “Satellite operators providing HTS services are using frequency re- use, which makes it possible to get more megahertz per dollar. A different example is the XChange box we have provided to more than 1,000 vessels, which combines different technologies like compression, caching, content filters and prioritisation.” Which of the available options are likely to be the best for an offshore operation using satellite communications rather depends on the type of operation, your company’s coverage and throughput needs, and the band or bands employed. However, the good news is that a wide number of companies offer products and services that can make more efficient use of limited satellite bandwidth options. They include EMC, of course, and Marlink but, for specific acceleration solutions, Wurst cites vendors such as Riverbed, Xiplink, Blue Coat, FatPipe, Cisco, Ipanema, Citrix, Packeteer, Expand Networks and Silver Peak Systems. And of course space segment optimization and effective utilisation of space segment resources is the focus of many VSAT technology vendors, such as Comtech EF Data, iDirect, Gilat, Hughes and Newtec. Wurst continued: “The leading optimization vendors offer several different combinations of IP WAN optimizing technology that suit specific purposes. Signalhorn’s role is to select and integrate the optimal data compression and bandwidth optimization technology to provide a tailor- made solution for our customer.” Marlink has a similar philosophy from the maritime VSAT point of view. “Providing ship owners all over the world with Ku, C, L and soon Ka and X- band services, we are well positioned to provide bandwidth- efficient communications because of our experience, network, partners and product portfolio,” said Olsen.
Noise Reduction System
As well as proven technologies for optimization, EMC has internally patented several technologies including not just Speednet but its NRS [ Noise Reduction System] technology, which uses its carrier cancellation capability to save inbound MHz. “EMC also focuses efforts on improved software for our SatLink product line to achieve portability of bandwidth to various locations or vessels within a network on demand and advanced network monitoring applications to manage bandwidth utilization,” said the company.
Limitations “Making something which is already compressed even more compressed is still difficult.”
But what are the limitations ( at the moment) of such techniques beyond which data compression or bandwidth optimization are no longer viable options? Quality of service is, of course, a necessary consideration. It’s also true as Marlink’s Olsen said that processing is faster than ever “but making something which is already compressed even more compressed is still difficult.” For satellite bandwidth optimization, however, EMC said, the industry is especially focused on improving the digital television broadcast standard DVBS2 and modulation techniques. Just over ten years ago we were talking about modulation techniques such as Binary and Quadrature Phase- shift keying ( BPSK and QPSK) and then 32 asymmetric PSK ( APSK). These days, “We are talking about 64APSK and 256APSK. New FEC [ forward error correction) steps and even sharper roll- off will also be part of the new optimization techniques. On the data side the progression seems to be toward faster and newer options for optimization.” All of which, in real terms, means that more bandwidth efficiencies are helping to deliver more advanced applications in locations with limited connectivity, and that companies can save money by making less bandwidth do more. Will this continue? It will have to. As Thomas Wurst said: “Today oil and gas companies are looking at ways to maximize their existing satellite capacity rather than just increasing capacity as their needs grow.” * The Abis interface is within the GSM architecture, between the BTS ( Base Transceiver Station) and BSC ( Base Station Controller).
Thomas Wurst, senior solutions engineer with Signalhorn