Industrial Leased Line Replacement

Seamless migration for legacy devices onto an Ethernet/IP or T1 network


Connect existing Analog and TDM interfaces over an IP/MPLS microwave or fiber network. This alternative network provides a more cost-effective and easier to maintain network for companies that previously operated on leased lines. Customers have the option to use a pre-built IP network or build one out. Since the new network integrates existing equipment, users are able to save time and money during transition.

The application diagram showcases a typical network that decided to upgrade to IP/Ethernet. Existing 4 Ch. FXS, 4-wire analog, and 4 Ch. Dry Contacts were kept in place. A combination of microwave, fiber, or MPLS is then used to replace leased lines. With this application, users can expect to have uncompressed DS0 (64Kpbs) direct to IP using the TC3846-6.

White paper: Navigating Leased Line Network Modernization

Another alternative to a copper leased line is the T1 line available from many Telcos. Users of this system will avoid dealing with prioritization requirements and cyber security headaches with no additional configuration.

When transitioning off leased lines users can expect extremely low latency and improved voice quality. The application diagram shows how one network was able to keep existing JPS SNV-12 Voters and Motorola Astrotac Receivers connected to 4-wire Analog Radios and the TC8614.

White paper: Navigating Leased Line Network Modernization

Case Studies

ESRN Eliminates Leased Line Costs

East Shore Radio Network (ESRN) needed a replacement solution to eliminate their leased line costs. Support for leased lines had also lessened in recent years. Finding a cost-effective and future proof solution was critical. ESRN was able to fully integrate existing equipment while improving audio quality.

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Preserving Essential Legacy Equipment with Leased Line Replacement Solution

A Northern California County needed to find a solution as soon as they knew Telcos were beginning to phase out analog leased lines. The county needed to find devices compatible with existing 4-wire analog radios, voters, and P25 trunked radio systems. Without being compatible they faced increased costs and network downtime.

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Multi-County Public Safety Agency Upgrades Microwave Radio Network

A public safety communications network in Iowa required a system-wide replacement to keep police, fire and emergency first-responders connected. Reliability of equipment had degraded and vendor support uncertain. Using a multi-service Ethernet platform, STARCOMM was able to improve audio quality and network management.

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Replacing Leased Line with T1

Facing disruption in critical communications when copper leased lines were planned to be discontinued, a town in New England was able to utilize T1 or Switched Ethernet services offered by the provider to keep emergency services in operation.

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"Over the past thirty-five years I have used similar boxes from other vendors for similar applications. But I have never seen one that would produce such a linear, uniform audio transmission from one end to the other - especially across an IP link."
- Martin T. Vinson, N.C.T., A.S.C.E.T.

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Many Radio over IP solutions are SIP based. SIP and VoIP can cause audio compression and have difficulty handling variation in latency. For a reliable and clear audio channel particularly for critical communications, TDM over IP technology is a better alternative.

Clear uncompressed audio, passing tones, and voter comparator compatibility can be achieved by using TDM over IP technology when designing a RoIP device for critical communications.

TDM over IP is a technology where it emulates Time Division Multiplexing over a packet switched network. TDM over IP takes a real-time bit stream and packetizes it. When combined with a special clock recovery scheme called Adaptive Clock Recovery* (ACR), this solution provides a low latency, reliable solution for clear Analog audio and tones over an IP network.

As a result, TDM over IP transported analog voice data is identical to a conventional Telco's 600 ohm leased copper line. This technology has been used for many years to transport T1 or E1 over Ethernet.

*ACR is used to recover the clock by counting the bits in data stream which is extracted from packets received.