Technology Solution

The sections below will explain how our technology works.
1 Evolution DVB-S2/ACM System
This section introduces iDirect’s implementation of the DVB-S2/ACM standard into the next generation Evolution product line and the unique benefits and components of iDirect’s Intelligent Platform™ enabling service providers to lower operating costs and increase their business opportunities.
Most system implementers continue to deploy DVB-S2 systems using the “broadcast” profile of DVB-S2, which is far from optimal for interactive VSAT systems. iDirect, on the other hand, has tuned every aspect of its DVB-S2 implementation for the efficient delivery of IP data across satellite networks, while still remaining 100 percent compliant with the DVB-S2 specification. Data packets in iDirect’s Evolution platform are carried using an efficient
encapsulation scheme based on the new “Generic Streams” mode of DVB-S2. In contrast to inefficient encapsulation schemes such as Multi-Protocol Encapsulation (MPE) over MPEG-2 Transport Streams, iDirect’s encapsulation scheme allows for variable length IP packets to be efficiently packed into DVB-S2 frames. The DVB-S2 standard also incorporates new modulation and FEC schemes, supporting QPSK, 8PSK and 16APSK modulations on the DVB-S2 downstream and enabling different coding and modulation schemes, including both Constant Coding and Modulation (CCM), and Adaptive Coding and Modulation (ACM). iDirect’s ACM uses an adaptive, dynamic algorithm that changes the demodulation scheme and the error protection level as often as each data frame, representing a major improvement over CCM.\ With iDirect’s Evolution product line, service providers gain critical new advantages in
bandwidth efficiency and availability gains. They can lower operating costs, expand into new markets and win new customers, all while protecting their current
investment. Network operators can start new hub operation or easily upgrade to DVB-S2/ACM through their existing hub investment, adding new Evolution line cards and remote routers along with new iDX software taking full advantage of all the benefits the iDirect platform has to offer.

1.1 DVB-S2 Support
iDirect’s DVB-S2/ACM system incorporates the industry’s most efficient data delivery physical layer solution. iDirect utilizes ACM optimized within the full system architecture in the first release of the product (not adapted into an existing, fixed CCM system).
we incorporates the following current industry-leading products and solutions:
• Integrated encryption, QoS and Group QoS
• Best-in-class Network Management System (NMS) built to monitor ACM in real
time
• Global Customer Support to optimize initial network design and provide continued
client support as the network grows

The DVB-S2/ACM system utilizes the Interactive Data element of the DVB-S2 Digital Broadcast standard developed specifically for VSAT applications through contributions from VSAT industry players. This implementation of the outbound or forward link channel by the industry represents the most efficient data delivery physical layer solution in terms of link efficiency (Bits/Sec/Hz) available today.

1.2 Adaptive Coding and Modulation (ACM)
iDirect has incorporated Adaptive Coding and Modulation (ACM) in the design of the product. Most DVB-S2 systems are relatively similar with respect to data efficiency of the broadcast carrier. Using the return-channel of an interactive data system, direct feedback from every remote in the system can provide real-time information to the Hub on how well the outbound link data is being received by the remote. The Hub can then, on a site-by-site basis, adapt the specific modulation and coding scheme to adjust for any degradation of the data link to each remote.

Figure 1: Adaptive Coding and Modulation (ACM)


The system is designed with the primary objective of optimizing the effectiveness of ACM in the iDirect DVB-S2 system. This provides the largest benefit in terms of system data efficiency gain overall for any DVB-S2 system. ACM Features unique to the iDirect platform include:
•Implementation of an efficient packing algorithm, especially at high symbol rates.
•Simplicity of configuration and deployment: minimal options for the customer to
configure through iBuilder for initial network set-up.
•Framing format optimized for ACM interactive IP data traffic.
•Bandwidth saving from using DVB-S2 coupled with bandwidth savings from using


ACM resulting in over 50% increase in efficiency.
Configuring an ACM system can be a complex process in order to achieve significant ACM gains in the final network design. iDirect has approached the implementation of ACM within the DVB-S2 system with simplicity as a fundamental engineering design criteria.
The iDirect system is designed so that satellite network designers choose the lowest C/N operating point at which they want the network to run (referred to as the lowest MODCOD), in a manner similar to defining a typical Ku-Band interactive data system. This is roughly equivalent to the worst-case link budget that would be used in a CCM system. The lowest MODCOD is used for all basic signaling and timing messages sent by the hub, such as the burst time plan. The ACM system will then automatically exploit clear-channel margin without any intervention by the network operator.

1.3 iDirect Intelligent Platform™
The advantages of iDirect’s Evolution product line are amplified through additional benefits of the iDirect Intelligent Platform™:
• Advanced IP routing capabilities that enable service providers to support critical business applications and seamlessly integrate terrestrial and satellite networks.
• End-to-end VLAN support that permits a remote router to have multiple VLANs associated with it.
• A single VLAN map to multiple remotes that allows QoS classifications to increase the network operator’s flexibility.
• Advanced security capabilities such as AES 256-bit encryption, TRANSEC and FIPS 140-2, all of which meet military and commercial security needs.
• Unequaled mobility support for land, sea, and air COTM: spread spectrum, automatic beam switching, and central management through iVantageTM Global
NMS.
• Virtual Network Operator functionality, which helps hub owners expand business through hosting capabilities, and lowers cost of ownership for service providers entering new markets.
1.4 Rigorous Simulation and Testing
The iDirect DVB-S2 development team dedicated nearly a year to rigorous testing and simulation to find the optimal way to provide the most consistent bandwidth gains along with a straightforward method for customer network design and upgrade. This included running multiple simulations for various ACM algorithms to optimize iDirect’s implementation of the standard within all elements (Hub plus remote) of the VSAT system. Other engineering approaches used during the development phase to maximize the performance level for the system included:
• Maximizing ACM performance and simplifying ACM network configuration as the primary design objective, not as an option or add-on to a standard DVB-S2 technology.
• Leveraging proven DVB-S2 IP Cores (Modulator/Encoder, Demod, and Decoder) from experienced suppliers• Building on the advanced NMS capability at iDirect to address the specific
configuration and monitoring (ACM-gain) requirements for ACM.
• Redesigning the hardware solutions (next-generation iDirect platform) for the hub line card and remotes specifically to handle the requirements for iDirect’s DVB-S2/ACM.
By driving the iDirect development effort along these key, high-level guidelines, iDirect’s goal is to have the industry’s leading implementation of DVB-S2/ACM.

 

1.5 System Performance and Characteristics
The following provides a summary of the technical enhancements incorporated in the DVB-S2/ACM system:
• Flexibility: more code rates and modulation types (QPSK, 8PSK, 16APSK)
• Maximum Symbol Rate: 45 MSym/s (fills a 54 MHz transponder)
• Data Rate: up to 156 Mbit/s using 16APSK
• Full support for ACM
• Utilizes proprietary MF D-TDMA upstream

2 iDirect MF-TDMA Star Topology
iDirect star topology network architecture consists of a very large broadcast carrier on the outroute and with multiple inroutes using Deterministic Time Division Multiple Access (D-TDMA). All of the remotes in an iDirect network share the outroute for their downstream traffic while all of the inroutes are shared by groups of remotes. The access protocol used on the inroutes is further enhanced by iDirect’s fast frequency hopping capability

An iDirect outroute is optimized for IP packets and provides the most efficient usage of satellite bandwidth. The outroute capacity is determined by the total demand required for all of the remotes within a network. An inroute size is based on traffic demand, the number of remotes and the CIR's assigned to the remotes, which must be balanced with the transmit power of the remote VSAT

Each inroute is broken up into multiple time-slots. A remote is assigned a minimum CIR within an inroute. D-TDMA, a technology that facilitates capacity sharing by dividing it into fixed time slices, allows a single allotment of bandwidth to be efficiently and effectively shared among multiple remotes. D-TDMA has been proven to be the most efficient in terms of throughput and satellite resource requirements.

2.1 Downstream Transmission on an iDirect Network
iDirect’s TDM technology is used for the broadcast downstream. This technology sequences, addresses, and transmits data packets in a manner allowing for
maximum utilization of assigned bandwidth. As IP packets arrive in random sequence at the Hub from the data center, they are sent out in a first in, first-out
sequence. All remote sites that are sharing this link are tuned to that common frequency and receive the broadcast. Packets are encoded with a unique identifier that is the permanent serial number of each Satellite Router. The outroute uses a modified HDLC frame that contains a full IP packet. This avoids any fragmentation of the packet over the satellite. This also achieves a high efficiency of the satellite space segment. Each outroute carrier can range from 128 Kbps to 20 Mbps (iNFINITI TDM) or 156 Mbps (DVB-S2/ACM) of Channel Rate. The technology allows for controlling the amount of bandwidth that is allocated to multicast traffic, QoS or GQoS assignments to each remote, and rate-shaping traffic by a remote. The iDirect outroute has built-in multicast capability and supports standard IP multicast traffic, with controls to rate-limit the multicast traffic per outroute

An iDirect Hub supports up to 20 outroutes per Chassis, with each having one or more inroutes. This feature makes the iDirect Hub one of the most flexible and scalable systems in the industry. One can have true private networks within the same Hub Chassis, with each network having its own characteristics. This also allows the use of non-contiguous bandwidth on the outroutes, as opposed to the stringent bandwidth requirements of a single outroute-based system. Application QoS settings can be used to prioritize traffic that is destined to a particular Satellite Router. One can also rate limit any site using the system rate control feature. Most of these configuration changes happen on-the-fly, without having to reset the system. In addition, one can configure QoS settings including application triggered minimum rate, maximum rate, and application QoS on a per Satellite Router basis. B.2.2 Upstream Transmission on iDirect Networks
iDirect inroutes or upstreams allow multiple remote sites to share the capacity. The upstream access protocol used by iDirect is called Deterministic-TDMA (D-TDMA). iDirect’s industry leading D-TDMA protocol guarantees fast response times and is known for the deterministic nature in which a network can be designed to meet any level of guarantees. The iDirect system allocates bandwidth to each site, based on traffic demand at the site and network operator imposed QoS restrictions. The system is constantly analyzing demand at all Satellite Routers and allocates bandwidth as frequently as 8 times a second. This type of architecture is ideal for networks that have bursty TCP/IP traffic, like most corporate LANs that also support real-time traffic such as VoIP. When compared to competitive solutions that use slotted aloha as an access protocol, the superior iDirect network architecture provides the infrastructure that allows companies to run applications such as VoIP and mission critical applications on a shared TDMA network. With Multi-Frequency (MF) Hopping, a remote can transmit data on its dedicated time slot for most of the traffic and as more bandwidth is needed, the remote can be allocated bandwidth on another inroute with sufficient bandwidth available. This provides a great deal of flexibility in designing a network, which saves satellite bandwidth while providing the required performance to its remote sites. As a result, a significant cost savings is realized in the overall cost of the network.

 

Figure 4: Upstream Transmission on an iDirect Network
iDirect’s Satellite Routers support of application based QoS provides prioritization and bandwidth guarantees to different traffic types at the remote sites. For example, one can prioritize VoIP traffic over data or prioritize database traffic over VoIP. Prioritization at the remote sites can be done on Source/Destination IP, Source/Destination Subnet, Source/Destination Port, DiffServ and TOS Bits, VLAN ID or by Protocol type. On the inroute, QoS when coupled with the system’s ability to configure a CIR and Rate Limit provides an enormous amount of flexibility to design a network that meets enterprise business requirements. iDirect has industry leading Traffic Engineering that is key to creating and grooming networks with maximum throughput and bandwidth efficiency. Traffic engineering allows a service provider to define and meet SLAs. The iDirect system has numerous features allowing one to implement a network that is properly engineered to meet customer needs and to provide application assurance. In addition, iDirect TCP acceleration mitigates the affects of satellite latency and
guarantees packet delivery in the event of packet corruption or loss. TCP acceleration performs this task by buffering packets in both the outroute and inroute
direction. By itself, this cannot provide improved web performance over a satellite link, but iDirect’s acceleration delivers the functionality required to support a highly responsive network for web applications. The iDirect system allows the routers to hop between inroutes based on traffic
demand. iDirect’s MF-TDMA allows for fast frequency hopping that happens on a burst-by-burst basis and provides the highest efficiency in capacity usage and allocation.

2.3 Teleport Architecture
iDirect Hub equipment is by far the most scalable and cost effective solution in the industry. Equipment can grow with demand, keeping capital costs following revenue

2.4 Hub TDM/MF-TDMA Network Control
The iDirect Protocol Processor (PP) is the heart of an iDirect system. A network can be managed by a single PP, or several networks can be managed by multiple load sharing (and redundant) PP’s. For timing synchronization and time plan synchronization, the frame length within an iDirect system is the same for all inroutes. The PP controls all real-time aspects of the network(s). This includes authenticating and acquiring Satellite Routers into the network, generating TDMA time plans, analyzing demand from each Satellite Router, dynamic allocation of bandwidth to all Satellite Routers within a network, TCP/Web Acceleration, QoS on the outroute, automatic inroute power control at the Satellite Routers, and AES link encryption. Each iDirect network can have a separate PP as its real-time manager. This makes the system very scalable and allows for completely isolated private networks. The iDirect system uses Ethernet as the transport mechanism to connect all devices together. Each line card within the iDirect Hub Chassis has its own Ethernet interface. This allows one to control which Ethernet segment a line card is present in, supporting the creation of real private networks. An iDirect Satellite Router becomes part of a network only after it has been authenticated and acquired into the network. Each router that is part of the network is defined in the NMS and is known to the PP. A Hub constantly scans for routers that have not been acquired into the network. All routers listen for a message from the Hub containing their unique address (serial number) defined within the packet. When a router gets a message, it transmits a burst in the acquisition time slot of its assigned inroute carrier. The Hub then fine-tunes the transmission (frequency and timing offset), before it issues the traffic slot within the TDMA frame.

2.5 Remote Support for Same/Multiple Inroute Carrier(s)
iDirect’s modular approach to service implementation and delivery allows a Network operator to implement and support any service type within a single or group of inroutes. This is unlike most competition where service types are dependent on the type of carriers. This provides a significant advantage to designers and network operators in both efficiency and cost of operations.

2.6 Broad Range of Inroute and Outroute Data Rates
The iDirect suite of products allows organizations to design a network to meet its business needs. As an organization bandwidth requirements change over time, with changing business needs or enabling of newer applications, the iDirect solution has the capability to reconfigure the network easily and with minimal disruption to service. The iDirect satellite routers provide IP throughputs of up to 20 Mbps downstream and 6.5 Mbps upstream on a burstable basis and with varying quality of service levels. These carriers’ rates can be changed in 1 bps increments.

2.7 Typical Remote Site
iDirect remote satellite router based architecture is straightforward. The remote router connects on one side to the Ethernet LAN and on the other side to the ODU (Outdoor Unit) with two co-axial cables. The ODU is powered by the remote through the co- axial cables. The system allows users to point an antenna with a voltmeter. Pointing does not require the use of a spectrum analyzer.

2.8 Remote Terminal Equipment
In addition to the standard antenna, block up-converter (BUC), and low-noise block down-converter (LNB) outdoor unit (ODU) components, the iDirect star/mesh terminal consists of the following components that are all integrated into a single indoor unit (IDU) chassis:
• Integrated Features – IP Router, TCP Optimization, RTTM feature (Application and System QoS), cRTP, Encryption, MF-TDMA, D-TDMA, Automatic Uplink Power Control and Turbo Product Coding.
• TDM Downstream Receiver – This continuously demodulates the downstream carrier from the hub and provides the filtered IP packets and network
synchronization information. The downstream receiver connects to the antenna LNB via the L-band receive IFL cable. The down-converted satellite spectrum
from the LNB is also provided to the D-TDMA receiver.
• TDMA Satellite Transmitter – The TDMA transmitter is responsible for sending data from the remote terminal to the satellite TDMA channels. All data that is
destined for the Hub or for other remote terminals is sent via this transmitter.
• TDMA Satellite Receiver – The TDMA receiver is responsible for demodulating a TDMA carrier for providing remote-to-remote mesh connectivity. The receiver will tune to the carrier based on control information from the Hub.