The New Science of Network Broadcast Transmission for Field Ops

AUBURN, MASS.—Not that long ago, getting usable video with a high-quality sound track from a field unit, and getting it quickly, would have been deemed an accomplishment. More recently, advances in land and helicopter microwave communications, as well as improved satellite and cellular transmission systems including 4G have made field broadcast operations considerably better—especially for ENG applications. That is, if you have a line of sight, good signal strength and plenty of cash to cover the costs.


Now, a new transmission solution known as ENGenesis has changed the parameters for mobile broadcast operations. It combines current BAS band microwave transmission with advanced Long Term Evolution (LTE) technology to dramatically improve transmission distances and handle multiple simultaneous field units. Already operational and field proven, ENGenesis extends the newsroom to the field by incorporating innovative IP architecture to enable high-bandwidth IP bi-directional connectivity of A/V streams, VoIP and internet traffic between multiple mobile vehicles or helicopters and studio base locations. Both station-to-station and truck-to-truck communication are also supported. And all without cellular and satellite airtime charges.

This next generation communications technology uses the 2/7GHz BAS bands rather than commercial cellular to provide broadcasters with a high capacity private network that ties all studio and multiple mobile field production units together. It enables full remote control of IP devices in the field from a centralized studio plus it delivers up to 50 percent greater sensitivity even in areas with obstructions such as heavy tree coverage. The result is a solution with higher performance, greater capacity and increased transmission distance…for less.


ENGenesis operates in either 5 MHz, 10 MHz or 20 MHz channel bandwidth and uses LTE technology for managing bandwidth allocation among user devices in broadcast trucks connected to a Receiving-Site-Node. The use of LTE technology allows the ENGenesis system to partition the available bandwidth into multiple logical channels for different types of traffic. This ensures that non-real-time traffic, such as file transfers to/from the truck, will not degrade the video quality. Additionally, encoders are integrated with the overall system management and will automatically adjust the encoding bit rates as new trucks come online in the same frequency.

The system provides two downlink and six uplink time slots for a network designed to carry the majority of traffic on the uplink. Uplink and downlink bandwidth allocation to individual truck mobile units is done in real time to ensure the most efficient use of the system resource and to optimally support multiple mobile units. The technology can efficiently schedule multiple truck mobile units in the same radio frame and across different radio frames. For added flexibility, bandwidth allocation can be manually adjusted by changing the time slot assignments.

An example of bandwidth allocation is illustrated in the following two truck scenario where both have the same bandwidth demand for uplink video streaming and two-way internet traffic. The ENGenesis system uses a higher modulation/coding combination to deliver the bandwidth to truck number one as it is closest to the receive site fixed unit, but uses a lower modulation/coding combination to deliver the same bandwidth to truck number two, which is further away. The use of lower modulation/coding requires the system to utilize more time slots to deliver the same amount of data over the radio link.


With exceptional front end gain versus conventional DVB-T systems, this new communications technology delivers superior image quality with a transmission range of up to 80 kilometers (approximately 51 miles) using simple, small-footprint antennas that do not require elevating masts on vehicles or directional antenna adjustments on towers or buildings.

Exceptional Quality of Service (QoS) allows broadcasters to set user and application data priorities to control traffic by field unit, by application within a field unit, or both. For example, A/V streams can have higher priority than background internet traffic. The QoS configuration is fully controllable by the operator to meet the network’s and user’s data priority policies.

LTE supports bi-directional data communication between the fixed unit and the mobile unit. Coupled with the QoS management, multiple applications including A/V streaming, Voice over IP (VoIP), file transfers and other internet traffic, can be multiplexed onto a single radio channel and prioritized according to QoS policy rules. In a bi-directional LTE system, a downlink pilot signal is always present. The operator can use this downlink reference as an aid for truck antenna alignment without having another operator at the network end for guidance.


The basic communication protocol in the ENGenesis system is the Internet Protocol (IP), which opens up the system for a number of other features and applications that could not be supported by the traditional unidirectional microwave system. These benefits include video transmission to mobile devices or even to streaming sites on the internet in real time as well as the capability for a Wi-Fi hotspot to allow reporters access to the station corporate network on their mobile devices. Using this functionality, the video being transmitted to the station can be locally monitored by the crews’ cell phones and/or tablets. The truck can also be equipped with a GPS receiver for asset tracking, as well as including GPS information into the video streams so that the video is automatically tagged with the location. If necessary, technicians at the station can use the link to manage the truck equipment (encoders, decoders, etc.) in real time.

Other benefits include a future-proof design as the ENGenesis infrastructure equipment is software upgradeable via the Element Management System (EMS). The user device is upgradeable over-the-air through the ENGenesis air interface without any user intervention. This future proof design allows the ENGenesis system to include advanced features in future LTE releases.

When compared to conventional technologies, the ENGenesis system enables broadcasters to gain a significant competitive edge by enhancing their field production operations with superior sensitivity and better overall performance and cost-efficiency.

Steven DeFala is the director of sales for Accelerated Media Technologies in Auburn, Mass.