How to achieve realinteroperability

Peter Clemons

Clemons Consulting

Agenda

• Why interoperability is needed• Different interoperability aspects• Role of IOP testing and evaluating results• Migration of legacy equipment• Procurement guidelines

Why interoperability is needed

• Source terminals from multiple vendors– The IOP process ensures compatibility

• Create multi-vendor system environment– Requires Inter-System Interface (ISI)

• Reduce dependency on system supplier– Requires COTS equipment and open interfaces

• Allow interoperability with legacy equipment– Requires support of multiple air interfaces

Multi-vendor terminal supply

• Multi-vendor terminal supply is the basis for the IOP process

• IOP testing confirms compatibility of specific features of the SwMI (TETRA infrastructure) with a range of Mobile Stations (terminals)

• The IOP results are published on the TETRA MoU website

Multi-vendor system supply

• Requires Inter-System Interface (ISI)• The ISI allows seamless operation of

multiple networks from different suppliers which then can operate is one network

• The ISI reduces the dependency on a single system supplier

• ISI is currently under development by a number of suppliers, and IOP procedures for ISI are established right now

COTS equipment, open standards

• Use of COTS equipment and adherence to open standards is the trend for future TETRA systems

• COTS equipment reduces the dependency on the system supplier for maintenance and repair

• Open standards allows the system operator to use third party products and create solutions themselves

Legacy equipment interoperability

• Interoperability with legacy equipment allows interworking with other agencies or user groups using different technologies

• Legacy equipment includes– Conventional systems– MPT trunked radio systems

• Interoperability may also be provided with– APCO-25 systems– Advanced PABX (VoIP) & Cellular systems

The IOP process

Understanding the IOP process

• IOP is not just a certificate: it is a very detailed report of tested functionality with many different technical aspects

• To understand interoperability in practice, it is necessary to– Look at the results of the individual test cases– Consider software versions and roadmaps– Read “between the lines” for fundamental

incompatibilities which may exist

Limitations of IOP

• The IOP results are applicable to one software version of the SwMI and MS only

• Only sets of Mobile Stations from one supplier are tested against a SwMI: interoperability between different MSs is not tested

• The IOP process does not cover more complex scenario’s, such as subscriber pre-emption and mixed voice and data

Inter-System Interface

The Inter-System Interface (ISI)

• The ISI is designed to allow roaming of subscribers between countries where different systems are installed

• No real ISI is available right now: current ISI experiments are based on conventional analogue interfaces

• Different, inherent incompatible ISI standards are proposed by the major system suppliers

How to solve the ISI dilemma

• Customers should demand compliance with ISI standards and work pro-active with the system suppliers to achieve this

• Specialized companies may provide solutions for bridging the different flavors of the ISI standard

• Use open interfaces (e.g. for dispatching) to create really functional system-to-system interfaces

COTS and Open Interfaces

Understanding COTS

• Commercial Off The Shelve (COTS) is the trend for building next generation TETRA systems

• Use of COTS allows mix-and-match of system components from different suppliers

• The Internet Protocol (IP) and PC technology are the main drivers for adoption of COTS

Benefits of COTS

• COTS reduces the dependency on the system supplier for maintenance and repair (no proprietary technology)

• COTS allows easy migration to platforms with higher performance

• COTS is more cost-effective• COTS allows selection of best-in-class

technologies at any time

Open interfaces

• Open interfaces removes the “black box” perception of TETRA systems

• Open interfaces creates a powerful basis for customizing TETRA solutions

• The main driver for open interfaces are the Internet Protocol (IP) sub-standards:– TCP/IP– XML– HTTP, SNMP

Legacy equipment

Legacy aspects

• Migrate existing networks– Continue use of existing terminal equipment

• Interworking with other agencies– Needed for effective cooperation

• Solution for rural and urban areas– TETRA is not the most cost-effective solution,

especially not for low-density, rural areas

• Looking to the future– Ensure compatibility with emerging standards

Other legacy aspects

• Tendency to mix the operator-controlled one-for-all model with blanket coverage with specialized systems for specific applications, such as:– Airports and seaports– Rapid response units for emergency services– Industry

►Maximizes control and minimizes operating cost (no subscription cost)

Procurement guidelines

Procurement guidelines (1)

• Don’t be tied up with one type of MS– Define separate procurement of infrastructure

and Mobile Stations– Insist on interoperability for all required

functionality, not only the IOP testcases– Understand the fundamental and sometimes

subtle incompatibilities of Class 3 encryption, DGNA, group attachments, Packet Data and ISI

Procurement guidelines (2)

• Don’t be tied up with one system supplier– Demand ISI compliance– Look for solutions with real open interfaces,

no only for Network Management, but also for voice and data integration

– Invite specialist companies to offer solutions for bridging incompatible ISI solutions and/or to utilize the open interfaces

Procurement guidelines (3)

• Make sure the system solution is future proof– IP-based, open XML interfaces, COTS

• Understand the breakdown in system component cost– Avoid sudden price increase when expanding

capacity

• Consider migration aspects

Thank you for your attention !

Questions ?