تحکیم شبکه های بی سیم امنیت عمومی: تجزیه و تحلیل اقتصادی مبتنی بر گزینه های از سناریوهای متعدد

The Korean National Emergency Management Agency proposed to replace existing public safety wireless networks of 46 agencies with a nation-wide consolidated network. This study compares the public–private partnership alternative of sharing a network with the conventional alternative of building a government autonomous network. Using exploratory modeling and real option analysis which compute path-dependent values (including network effects and switching costs) of all the plausible sequential incremental investments against a wide range of future states, this study has designed adaptive investment strategies (“start robust, then adapt”) which start in the highest pay-off area, and then make investment decisions about whether to expand or switch to lower pay-off areas, based on an updated information of technology prospects and the previous-stage performances of inter-agency operational effectiveness and public–private partnership. This case study has demonstrated that well-designed adaptive investments will enhance long-term values and reduce downfalls arising from public–private partnership.

Public safety officials have unique and demanding communication requirements,1 so they cannot just use cellular phones for mission-critical communications during serious accidents. Most public safety agencies operate the old analog radio systems in the very high frequency (VHF) band or the ultrahigh frequency (UHF) band. Old VHF/UHF-based systems use the wideband of spectrum resources inefficiently, and most of them are not interoperable to each other across different agencies. The trunked radio system (TRS) greatly enhanced spectrum efficiency and improved collaboration and synchronization capabilities by allowing communications with anyone (e.g. dynamic grouping2), anytime (through priority access and immediate access time) and anywhere (through direct connect mode). Enhanced connectedness enables various public safety agencies to share information in real time, and hence better respond to emergencies by rapidly mobilizing the complementary resources of several agencies. However, an inability of existing systems to communicate between public safety agencies may hinder effective disaster response or even put public safety workers in danger. On September 11, 2001, New York police helicopters relayed a message for public safety officials to evacuate the north tower of the World Trade Center, but firefighters never received it and 343 firefighters died, because their radio system was not interoperable with the police communication systems (National Task Force on Interoperability, 2005). On February 18, 2003 in Daegu, Korea, a fire in the subway rapidly turned into one of the country's worst disaster. Of about 192 people died and 148 people were injured. A stationary train caught fire, but another train traveling the opposite direction, receiving no warning message. Most people died in the second train, when it arrived at the station and stopped alongside the blazing train (MOGAHA, 2003). Becoming aware of such problems, some governments began to pay attention to the need for improving interoperability among public safety agencies such as law enforcement, transportation, emergency medical services, fire, utilities, military, fleet management, disaster recovery and so on. The highest degree of interoperability is achieved when all the government agencies agree to migrate to a single communication system which provides coverage for all. Governments also can save money, because the fixed costs of construction and maintenance of infrastructure can be shared, and variable costs such as the prices of user equipments can be lowered, because of volume discounts (Peha, 2007). However, most public safety agencies have already built their own legacy networks redundantly (i.e. sunk costs), so the nationwide replacement of their legacy systems with a consolidated state-of-art network is very expensive.3 Moreover functionally divided bureaucracies, fragmented planning and funding, free rider, and spillover effects discourage collective investments in shared standard services which will benefit a number of agencies and divisions. The migration towards interoperable wireless networks can be organized by a government-wide coordination task force or by individual agencies which need it most. The migration approach can be achieved through either the switch of the entire networks all at once or incremental and backward compatible upgrades over time. Fig. 1 summarizes various types of migration approaches in quadrangle.The U.S. SAFECOM initiative serves as the umbrella program by the President's Management Council to guide and coordinate the evolution of local wireless networks over time. SAFECOM adopts a long-term evolutionary approach to achieve an integrated system-of-systems by 2023 (Boyd & Orr, 2004). On the other hand, the U.K. AIRWAVE is the first nationwide consolidated public safety wireless network in the world, based on the most expensive technology (TETRA) to satisfy the police requirements which are the most demanding among public safety agencies. However, other agencies refused to join the Airwave, since they considered that it does not add much value to their operations, but may add significantly to the cost (NAO, 2002). The Korean National Emergency Management Agency (NEMA), as the central leadership for disaster management, ambitiously proposed to replace the wireless networks of 46 public organizations (12 central government agencies,4 16 provincial and metropolitan governments and 18 public corporations5 ) over three years with a new nationwide consolidated network based on a TETRA technology which would cover 40% of the national territory. Since a new system, based on radical innovations with wide-ranging effects on public services, will replace, rather than build on, existing systems, the value gained from it is subject to various internal and external uncertainties, and particularly interaction risk. If such investment is not matched with an inter-agency operational capability, consolidated networks will be left under-utilized. To mitigate diverse uncertainties, strategic experimentation is important. Investment managers need to periodically monitor multiple measures of internal performances and external conditions and flexibly redirect investments by adjusting the scope, timing, and scale of consolidation to capture opportunities and mitigate downside losses (Amram & Kulatilaka, 1999). This study will illustrate how adaptive investment strategy can be designed with the aids of exploratory modeling and real option analysis. Exploratory modeling or real option analysis will generate all the plausible paths of sequential incremental investments over time against a wide range of future states to help managers “start robust, then adapt” (Light, 2005). That is, before the actual launch of the project, exploratory modeling identifies a choice of opening standard in the first stage which will lead to the most robust long-term outcomes and designs of a roadmap about when to expand, switch, or abandon network platforms over the investment lifecycle.

5. Conclusion Nationwide consolidation may make the most advanced TRS network (that no single agency can afford alone) affordable. However, various uncertainties associated with an inter-agency operational effectiveness, technological advancement, and evolving service demands make investments in a consolidated network difficult. Public–private partnership may mitigate some of these risks and leverage the existing commercial infrastructure, but it may also create other kinds of risk. Using exploratory modeling and real option analysis, this study has designed adaptive investment strategies. The three-stage adaptive investment model has started in the highest pay-off area, and then made investment decisions about whether to expand (or switch) to lower pay-off areas, based on new information of the previous-stage performances, technology prospects and evolving services demands. This case study has demonstrated that well-designed adaptive investments will enhance long-term values and reduce downfalls arising from the public–private partnership. While this case study illustrates how to design adaptive strategies, implementing adaptive strategies is another difficult task. In order to actually implement adaptive investment strategies, key performance metrics for inter-organizational (cross-agency or public–private) communications (with different governmental agencies or other non-governmental organizations) need to be defined in advance26 and the baseline performances are measured before the program implementation. Examples of performance metrics include the proportion of inter-organizational phone calls among the total number of phone calls, the number of various governmental and non-governmental organizations which have been accessed at least once, the success rates and the speeds of inter-organizational communications, and so on. Through literature survey, regression analysis of actual data, and survey of experts' opinions, the government should determine the target level of performances that is required to achieve the expected value from a new consolidated network. The actual improvement of performance from the baseline must be carefully measured at each stage by investigating the databases of network operators. By comparing the actual performances and the target performances, the effectiveness of cross-agency collaboration or public–private partnership can be estimated. This ex-post measurement of performance improvements as well as the updated information of market growth and technology development will guide the actual implementation of adaptive investment plans. The detailed design of key performance metrics and implementation plans will be needed as an extension of this research. Finally, although this study has assumed that the TETRA-based network is dedicated to public safety use only, one may consider, as another public–private partnership alternative, that the TETRA-based network could be built by private funding and shared across the public and the private sectors. Since TETRA is a little more advanced technology than an iDEN, such public–private partnership may enhance the commercial communication services as well. Analysis of this alternative will be another potential subject for future research.