Other Perspective on Innovation and EM

Professionals of Electronic Monitoring (EM) are talking about what is missing in current EM solutions and why they don’t notice any significant improvements, not to mention innovations. I heard a lot during the years about such anticipated improvements/innovations. Just to mention a few:

  • Communication with the offender
  •  Inter-agency work
  •  Supporting decision makers
  • Comprehensive reliability

Usually, the hidden assumption is that these “goodies” should originate from the EM vendors.

In this post, I would like to focus on some of the reasons explaining why the vendors don’t meet the expectations, and specifically on how the procurement process affects it.

Before analyzing the reasons, lets put things in context. The EM industry presents almost the same solutions for already many years. You will probably not be able to identify new significant features that did not exist 10 years ago. If you visit the CEP conferences, you see almost the same, each session. The only new and significant feature that I can recall, during the last several years, is the fingerprint verification.

Innovation, from my perspective, is something that will be a game changer.

 A few examples:

  • A new approach to communication with offenders via the EM system
  • Information rather than data generated by the EM system
  • A new bracelet approach that reduces the 24/7 physical and mental weight

Why don’t we see such innovations?

Let’s look at a life cycle of a typical EM contract period: after a tedious process of a tender and appeals, finally the contract has been signed and deployment started. From this phase on, the EM operators are mostly busy with the daily life of the program, focusing on the primary goal – supervision of the offenders. Most operators are not technology driven, and neither should they be. They don’t have the time to investigate new options for improving their work performance and neither to explore options for achieving the social goals.  So, at the end of the contract period, they are familiar with their own system. Equipped with their system experience, the operator is now required to formulate a new tender. In the common case, the new operational and technical spec parts of the tender would look like the current system plus some items that are kind of modifications. It means that even if the current system contains deprecated technologies or limitations which no longer apply, these are perpetuated. While reading a typical tender specification, one can get the impression that most of the requirements deal with the internal work flow and less about topics that should drive the original EM social goals. Even when the EM customer has a great new idea that can enhance the system capabilities, writing it, for the first time, in the tender spec, is too late, since the development phase may take much longer than the tender due date.

The vendors, on the other hand, cannot take the risk of developing new significant capabilities. At the end of the day, beyond the requirements, there is always the assumption of the “good old” app, or “more of the same”. If this new capability is unique, it will most likely not be a mandatory requirement and, as an optional one, cannot guarantee sufficient compensation (In tender terms), that can justify the vendor’s risk. Think about a vendor that develops a video communication between the agency personnel and the offender. Development of such a capability costs a lot, in terms of human resources and technology investment. If this vendor is not convinced of getting a competitive advantage – it will not go for this risky adventure. This vendor will prefer to fix some bugs or add additional filtering that may add something.

One may ask, what is the difference between the EM industry and other industries, in this context?
I assume the followings are:

  • In most industries there is a continuous dialog between providers and customers, even if not formal. Example are enterprise software providers receiving feedbacks from customers, hundreds (and maybe more) of specific conferences enabling the collection of the “customers and providers spirit”, many posts and internet information, etc.
  • The industry market size – Since most of the EM projects in Europe are small, most of the vendors are struggling with relatively low revenue projects. Each new developed capability is divided among a relatively small number of subjects. Within this ecosystem, the vendors must increase their certainty concerning their development efforts.

To summarize:

  • There is a gap between the policy makers, EM program managers, procurement department and the EM vendors. Usually, the vendors have basic communication with the EM program managers and procurement managers, but not a continuous dialog with the policy makers and influencers.
  • There is no mechanism to facilitate: raising an idea, checking, testing, creating a demand and implementation of new capabilities
  • Most of the tenders’ specifications are almost the same as the current system
  • There is no process supporting improvements and new capabilities

What can we do about it? In next posts.

Second thoughts about Alcohol Monitoring?

About six years ago I led a group of professionals who had to submit recommendations regarding development of a new Alcohol Monitoring device. The most important aspect that we had to analyze was whether there is a real demand for Alcohol Monitoring devices among the responsible agencies.  We started our work with the understanding that alcohol consumption is one of the major causes to domestic violence and other crimes.

Surprisingly, after deep dive into the research we couldn’t find any evidence that a growth is expected in this type of devices. In Europe the overall demand looked like nothing (The picture, in the US, by the way, is slightly different. There is a usage of Alcohol Monitoring devices, but, the growth rate was not significant, if at all). The recommendation was to avoid, at that point in time, the development of a new device. During the years after, we tracked the trends and found the recommendation justified.

We couldn’t be sure about the reasons. We heard “it is interesting”, “the alcohol consumption is part of domestic violence” and more, but we couldn’t find the agency or country in Europe that is going to make such monitoring. I heard the reason that the alcohol consumption is part of the human rights and the problem is the violence and not the alcohol. I don’t know if this is the reason, or maybe others exist, but the fact was that there is no demand, in Europe.

Are there second thoughts in the UK?


Before starting GPS program


The two main technologies in use for monitoring offender’s whereabouts: location tracking (a.k.a. GPS) and proximity sensing (a.k.a. RF)

Theoretically, location tracking is the general case of tracking everywhere including at home.

Proximity sensing enables a supervisor to check whether the offender is near a specific home unit (HU). The hidden assumption here is that by knowing the location of the home unit we can tell the location of the offender, but only when they are in proximity with the HU.

The location tracking technology, can deliver the home detention capabilities but also can report about the offender location even without a proximity to other units, seemingly, everywhere.

It looks like the perfect location tracking and monitoring solution, can make the RF technology unnecessary, but……. we are still far from having a perfect location tracking solution.

Because of that, the selection between the two common technologies is based on many “compromise matrices”. These matrices include axes like what we would like to achieve, vs. offender type, risks, cost and others. As an example, let’s look at a case where we want to enforce an exclusion zone of a neighborhood where the ex-wife of a supervised person is leaving. If this person is organized and can be responsible for charging his device – the location tracking is suitable for him. However, a similar case with a different person who is not well organized and cannot take care of the device charging requirements, may change the decision about the appropriate technology. This unorganized supervised person will probably be under RF technology, confined to his home, in order to protect the potential victim. Part of the implications of this decision are the inability of the supervised to keep working and do essential activities out of home.

In this example, the “compromise matrix” is taking into account the location tracking technology limitation of requiring the supervised cooperation to charge the battery. In other cases, the limited ability to monitor indoor location will be dominant.

Questions we should ask ourselves before deployment of location tracking

  • What do we want to achieve, who are the offenders we want to supervise by location tracking: Controlling prisoner on leave, supervising sex offenders, eliminating offenders associating with each other, domestic violence, etc. Each target may have different implications and needs. E.g. supervising sex offenders may require support of Point Of Interest (POI) exclusion enforcement such as kindergarten and schools. “Prisoners on leave” means strict procedures regarding logistics, maintenance and charging of the equipment in and out of prison, performed by the prison staff and the prisoners.
  • Should we use 1Piece or 2Piece and what are the implications, what is the appropriate offender type for each of these solutions?
  • Who are the users of the system? the probation officers who would like to verify the zones regime is kept, or police officers who would like to use this tool for investigation purposes?
  • Do we align with the appropriate human resources to support location tracking program?
  • Do we align with the appropriate working protocols and profiles?


  • Defining goals and measures (KPI), such as:
    • If the target is to improve the control of a prisoner on leave, compare between solutions of with vs. without location tracking.
    • If the goal is to improve public safety, the control of sex offenders should be compared (what against what? Need at least 2 items for comparison)
    • If rehabilitation via integration with the community is a goal, compare the performance of location tracking vs. home detention
  • Identifying who are the stakeholders (probation officers, police forces, Judges etc.)
  • Writing working protocols – How to define the zones, what is the minimum size, warning zones, handling events, installation procedures (location, process), etc.
  • Organizing the equipment logistics
  • Educating the offender – comparing to the RF technology, the location tracking obliges offender cooperation, by, at least, daily charging of the device
  • Pilot is essential before starting operational program.
  • Location tracking means more supervision resources. The fact that location tracking depends on the offender’s cooperation for charging means more treatment compared to the RF technology, from the operator’s side. Another aspect that causes more complexity is the additional dimension involved: while a violation of home detention refers, usually, to a predefined location which is the offender house or work, the location tracking violation involves the location dimension as part of the equation. Because of that, the normal time that is needed to evaluate RF violation is shorter than in the case of location tracking.
  • Prioritization – Based on violation severity, risk assessment, offenders classification

Ethical and professional standards in Electronic Monitoring

I recently reviewed (again) the Recommendation CM/Rec(2014)4 of the Committee of Ministers to member States on electronic monitoring. I find it to be a definite manifesto of Electronic Monitoring in Europe.  This document covers the ethical standards of Electronic Monitoring programs. What makes this guide stand out is the fact that it is written from the perspective of a side that recognizes Electronic Monitoring as a solution that can help improve communities’ safety and enable subjects’ rehabilitation.

While reviewing the European Council recommendation, I came across a report written by Prof. Mike Nellis ( somehow, I missed it in the past..). It builds upon the European Council report, taking Electronic Monitoring discussion a step further, transforming the recommendations into more detailed guidelines; and comparing various policies and approaches to EM.

I am convinced that these two documents should serve as the main directives of Electronic Monitoring programs flow from start to finish –  from ethical, legislative, and social perspectives.

In fact, the social and legislative aspects of Electronic Monitoring programs are well covered by the leading minds of the field. The guidelines mentioned here as well as other documents available today, revolve around a somewhat progressive concept that aims to enable communities’ safety while focusing on offenders’ rehabilitation and reintegration into society.

The technological side of EM programs, however, has not caught up with the theoretical side quite yet. From the technological side of things, there are quite critical questions that require thorough consideration, such as:

  1. How can EM solution support different countries’ requirements re location points? Some countries collect the location points while others only detect exclusion and inclusion points bound to the country’s privacy laws. Some countries can use location points for investigation of certain activities, others cannot.
  2. What key features must EM systems possess to fully support government agencies in adequate handling of offenders on EM? (Reports, knowledge, communication, schedule etc.)
  3. What is the appropriate balance between computer based capabilities and the personnel involvement when coming in a contact with a human being? Should EM system send automatic voice messages to offender, upon a need, or should an interaction with the offender be only initiated by another person?
  4. What are the necessary measures for data protection?
  5. How can we use the “big data” collected by the EM system to provide a beneficial information to the government agencies?

These are just a few examples of what EM system should meet, refer and propose solutions.

For EM programs to be applied in the closest way possible to the envisioned concept, it is imperative to create technological standards and requirements.

These will, in turn, generate Electronic Monitoring programs that actually meet policy-makers’ requirements and fulfill the vision of safer communities and offenders’ rehabilitation.

What are your thoughts on a matter? What are the most acute technological challenges in the EM program that you are involved in? In what ways, you think EM program should use the technology to better serve the community? I would like to hear from you! Drop me a line.

How to prepare a new tender – Part 2

Function vs. Technical and Operational

Specifying functional requirements is tricky: The functional requirement of “reporting subject location in real time” can be interpreted as a 1-Piece or 2-Piece solution, reporting each minute or every 10 seconds, with a precision of 10 meters or 5 kilometers in different probabilities, and the battery will maintain 36, 24 or 6 hours depending on the usage profile. Another functional requirement can be “the equipment should be upgraded”. It is quite clear that upgrading the equipment via remote access is much more “operational friendly” than collecting all equipment and upgrading it in the lab. The communication between the field devices and the back-end servers is an essential aspect of the EM solution, but security and reliability is part of the demand. Those parameters are not EM functional requirements, but a kind of sideways requirement.
All the examples are here solely to help you understand that the separation between functional, operational and technical requirements is artificial. In many cases all aspects of a requirement are connected together without practical distinction. It is crucially important to understand all implications of each requirement, in order to define exactly what you would like to get and be able to test it before your final decision.

As always, as long as you know more, your position in front of your suppliers is better.

Guidelines for writing the requirements

  1. Know the details of your functional needs. It sounds simple, but it isn’t. This is actually the first phase while working on a new project.
  2. Be precise with the translation of the functional needs to the technical and operational spec. For example, if there is a functional need to have a home detention capability, you should define the precision of the solution (the apartment borders should be very accurate, or the apartment neighborhood will be good enough); based on that other aspects are then derived, such as secondary verification method, false alarms, RF range configurations, etc.
  3. It is essential to be familiar with all aspects of the EM solution and also about the market offering, in order to create a realistic tender on one hand and get what you need on the other. For example: Can the GPS solution be based on the back-end server calculations or do you need better performance? What are the legal requirements for alcohol monitoring; is yes/no sufficient, or is an accurate blood alcohol concentration level needed?
  4. The operators and managers of the EM system should have close communication with the tender writer.
  5. It is highly recommended to define the new tender requirements based on educated working protocols. For instance, before defining logistics requirements, you should know what your logistics facilities are, how you intend to move the home unit from the warehouse to the installer, how you will change units in case of installation problems, etc.
  6. Clearly define what the mandatory requirements are. These should be based on your needs, and also on what is achievable. You don’t want to be in a position where you specify a mandatory requirement that no vendor can meet.
  7. On the other hand, remember that the imminent contract will take place for the next 3-7 years. Many things may be changed. Be open! As an example, API is not necessarily what you need today, but it can be your way achieving other capabilities in the near future. API is also quite a common offering by the vendors. Consider asking for that in the tender.
  8. Reliability is king – Because of many reasons, the EM solutions do not meet the reliability expectations from technological system. I’ve heard from many EM program managers that as a mandatory requirement they “want the system to work as it should.”
    The tender should reflect two aspects regarding reliability: a) There should be reliability requirements that specify concrete targets (e.g. system availability, false alarm rate, water resistance, etc.); and b) You will not be able to check all reliability aspects by the written submission (e.g. application usability, installation, RF coverage, etc.). You should thoroughly test the system before making the final decision.
  9. Specify each requirement in specific and measurable terms. For example, “A fully charged device should hold for at least 36 hours in the following typical usage scenarios: GPS sampling rate: 60 seconds, communication rate: 300 sec,” instead of “the device should hold for at least 36 hours.”
  10. Bear in mind the tracking capabilities you need: each element should have a Serial Number (S/N), and a predefined lifetime. Even if you are not paying for a replacement (in the case of a lease contract, or any other guarantee arrangement), there is a huge operational and efficiency differences between a lifetime of 3 years or 2 years for a GPS device, for instance. It is highly recommended to ask for the technical reports about how this lifetime is calculated.

This is only a partial list. If you find it interesting, please reply with your specific needs and I’ll do my best to elaborate.

Dreaming of a Better World or Why We Must Push for Standardization of Electronic Monitoring

Imagine….  Electronic Monitoring is no longer based on the electronic bracelets, but rather, on a cutting-edge no-tag, self-installing solution that seamlessly interfaces with a user-friendly and flexible application that can be managed on the move. The EM programs manage all the stages of offender’s rehabilitation from in-facility tracking to location-based tracking outdoors. The EM solutions become so advanced, in fact, that now you not only can monitor offender’s whereabouts, but also health, levels of stress and mood, amounts of daily physical activity, calories consumed and burnt and much more. It is very clear how cost-and-socially-effective EM programs are, and they become part of a golden standard for rehabilitating prisoners, adopted by almost all the governments of the world.  As a result, the EM vendors are now a part of a much larger market, and so they see their revenues grow. The EM becomes a domain of progress and innovation, enabling safer communities and better world, while becoming a part of the eco-system of Smart Cities and Internet of Things.

There are reasons for the separation of this idyllic example. One of the most important is:

Lack of Standardization.

Why is standardization so important?

Industry-wide standards play a vital role in our globalizing world. Standards make an important contribution to national and international competitiveness.

Standardization does not just facilitate the transfer of knowledge but also the opening up of markets.

Standards support the innovation capability of enterprises for products, services and management by creating objective and internationally recognized parameters, targets and yardsticks for business activity.

They create leeway for innovation. Experience clearly shows that new technical standards often give a foothold to new technologies.

Standards are also a great help for the legislator and the administration. They provide assistance in the technical and practical implementation of legal requirements.

With civil servants participating in the drawing up of standards in their respective areas of expertise, standards can improve the description and implementation of legal requirements (http://www.directionsmag.com/entry/the-impact-of-international-standardization/123376).

Experience clearly shows that new technical standards often give a foothold to new technologies. Various industries ( e.g. semiconductors, environment,  energy, healthcare, transportation and many others) have successfully worked on and adopted international standardization which turned out highly beneficial for all the market players.  What were the benefits? –  Interoperability of products and services, innovation, improved design and quality of products, easier access to international markets and markets growth, better communication between manufacturers and suppliers and other benefits.

Why does Electronic Monitoring need standardization?

Today, a typical EM solution is the one where a single vendor provides all of the system components, creating a great deal of vendor dependency. Vendor dependency leads to mediocrity, stagnation and high solutions cost; the customers (government agencies and, ultimately, taxpayers) pay the high price. It also creates a distorted picture of EM program’s efficiency making EM’s progress harder to measure and analyze, as customers’ only source of information is vendor-based and with virtually zero objective information available.

The idyllic example at the beginning of the post might be a bit far-fetched but it comes to illustrate how standardization and interoperability can greatly benefit both the government agencies and the vendors.

If we can start turning the standardization wheel now, in the near future we should be able to achieve:

  1. Interoperability between solution components of different vendors – mixed vendor solutions, for optimal technological and budgeted solutions.
  2. Ease of integration with zero-touch provisioning.
  3. Improved hardware quality, durability (e.g.- battery life, location services) safety and performance.
  4. Better data analytics and information gathering.
  5. Adoption of “Best of Breed” approach, enabling technological and service excellence and implementation of new, out-of-industry technologies.
  6. Unlocking of the new markets and new revenue streams generation for the EM vendors.

 Archibald MacLeish said, “There’s only one thing more painful than learning from experience, and that is not learning from experience.”

 If nothing is done today, I believe, that our entire industry might pay a heavy price tomorrow.


What are your thoughts? Please share your comments and thoughts on the idea of standardization and interoperability. I would love to know how you perceive this concept, via https://www.em-is.com/index.php/contact/ or mail to emis@em-is.com 

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How to prepare a new tender

Whether it is the first, second, or even third or fourth time you are going to prepare a new tender, there are still many aspects you should take into account and be aware of.

I cannot overestimate the significance of preparing a good tender. This is where you, the customer of the EM system, are going to declare what exactly you need, your preferences, and mainly, what you will get as your Electronic Monitoring (EM) system.

Impact of the selection phase on the daily operation of the EM system

Beside classical aspects of procurement, such as price, payment conditions and other commercial aspects, the tender for purchasing or leasing an EM solution defines the actual system the program managers and operators are going to work with on a daily basis. In most of the cases, the tender requirements are part of the contract and the EM vendor’s commitments are derived from it.

The following are crucial parts during the selection phase:

  • Precise description of the needs – the functional, operational and technical requirements
  • Evaluation phase – verifying all mandatory requirements are met. Used to shorten the candidates list
  • Testing phase – Check the aspects that cannot be precisely defined, verify the vendor’s submission is the reality
  • Acceptance tests

The requirement definition phase is where the EM program managers should express their needs. Typically, these requirements bind both sides. The mandatory requirements should be fulfilled by the vendor, but these are also a kind of a customer declaration: “This is what I need.” In many cases the contract authority cannot change, add, or remove after the tender is published. There are many requirements that can be defined precisely in the tender’s documents, such as maximum weight, dimensions, etc., BUT, there are some that are not practical to be described precisely as a tender requirement. You, as the operator/manager of an EM system cannot describe precisely attributes such as usability of the EM application, ability of the system to be configured per the needs, the quality of information the system provides, installation aspects, etc. In addition, there are some points that can be interpreted by the vendor in a different way than the EM program manager’s intention. As a result, the written submission may be accordingly. On the other hand, these are the most significant attributes from the daily operation perspective. By definition, as you cannot write a precise description of how you would like to see the “scheduling” screen involved with the “violation” screen and how to scroll between maps and alert screens in order to investigate an event, you cannot evaluate the submissions of the tender in order to fully understand what you are going to get. There are also aspects that are geographically dependent, such as location tracking and RF performance, communication, etc.

Thus, you should describe the way you see these attributes, but the important statement here is – you must test the candidate system. Demo of the system is not enough, since you cannot get the right impression, you cannot thoroughly check the aspects in which you are most interested, and you may be biased by others.

You should specify in your tender condition the need of a thorough testing phase. If this is done effectively, this phase can be ended after 5-10 working days. The testing phase should include massive work with the application, installation tests, events investigation, system management, location tracking performance (outdoor and indoor), RF coverage, false alarms rate, communication availability, all according to pre-defined working protocols (if you don’t have such, it is highly recommended to establish it), and a comprehensive testing plan.

The efficient testing phase should include tests of the items that cannot be evaluated by the written submission and a comprehensive conclusion document that specifies the performance, points that should be improved as a condition for final decision and a proposal for a working plan to complete the needs during the contract period.
Based on the testing phase, you will be able to understand what are the strengths and weaknesses of the system under test. You will be able to derive the exact points that you, as a customer of the system, would like the vendor to change or improve. These points can be discussed in the next phase of negotiation.

Making the right selection and constructing the appropriate contract will let you know ahead about the important aspect of the candidate system, be aware of the advantages and limitations, matching between your needs and the supporting EM system, saving a lot of unexpected resources (HR, time, and money).

Keeping Privacy While Tracking

What does “privacy” mean in EM Location Tracking context

One of the most troubling aspects (mostly in Europe) while tracking an offender by a “GPS” device is the privacy. My interpretation of it, in this sense, is that the authorities respect the offender’s right to keep his location information to himself, unless this offender performs any breach. In most of the cases, the usage of GPS tracking is to enforce exclusion and inclusion zones (special zones) regime. So if this is the case, why do we need to collect location information while not in the special zones?

What are we trying to achieve with GPS tracking

From the supervision agency perspective, the “GPS” tracking intends to supervise the offender out of his residential place. Trying to understand what it means “to supervise” brings me to the following options:

  1. Knowing the location of the supervised subject continuously (very high risk, privacy is not an issue, etc.)
  2. Enforcement of special zones

The location tracking solutions, currently, are serving both options without distinction between the required option. Even if the agency is not interested with the location points of the subject while not in a special zone, the devices are reporting their lat/long points (the location information) which are saved in the memory and data-base of the EM system.  I wonder why it is needed for the second point, why do we need to store all location points even if not in the neighbourhood of the special zones? I guess the reason is that from the technology perspective it covers all options. On the other hand, when the agency wants to keep the offender’s privacy, these registered points are prohibited.

 How to combine privacy and GPS tracking objectives

The answer is quite simple: let the device report its location only while offender is in violation, such as crossing exclusion zone, or missing the inclusion zone.

There are two main approaches the EM vendors are taking with regards to the “GPS” device capabilities:

  1. Using a relatively simple device without significant calculations capabilities. The backend EM system is taking care of all calculations. In this approach, most of the devices are not aware of the special zones. They report all the location points and the EM backend system calculates whether there is a zone violation. In such architecture, it is obvious that locations points should be uploaded into the system. This is the first breach of privacy.
  2. The other approach brings almost complete independency of the location tracking device. These devices are aware of the special zones, they can calculate whether there is a zone violation or not and they can keep many location points in the internal device memory. In addition, these devices report the location point.

Using the second approach devices and disabling the upload of the location points can serve the enforcement of the special zones while maintaining the offender privacy. In order to support high reliability of such an approach, it is highly recommended to have “secondary evidence”, by another location mean, such as LBS.

Another advantage of such an approach may be increased battery life. If there is no need to upload routinely the location points, the device can decide on the enable/disable location mechanism. If the offender is far away from a special zone and movements are low, the location mechanism can be disabled and will extend the battery life.

We will be happy to get your thoughts and feedbacks in order to better understand if this approach can mitigate the conflict of privacy and offender tracking. You can send your feeback here, or by email to emis@em-is.com.

GPS Location Tracking For Electronic Monitoring – Part 2

In this part I’ll describe the most common approaches for location tracking, the one and two piece solutions.


  1. 1Piece

The 1Piece solution is a single unit attached to a subject’s ankle. It can compute location and communicate with backend (EM) servers via a cellular network. In recent years, most 1Piece products have also been able to communicate with HUs via RF, so the 1Piece can be used both for location tracking and for home detention. In theory, this device covers everything; location services while outside the house, and RF proximity in house (or work)  where GPS is unavailable.

Vendors provide different types of home units. Some use RF receivers, while others use special “Beacon” equipment, which usually has a subset of RF features, like a Beacon without independent communication ability. In this case, the 1P device is still responsible for communication with backend servers. Beacons may be very small and battery-operated, rendering charging unnecessary.

Traditionally, the 1Piece is charged by connecting it to an outlet via a wired charger – in effect, connecting the subject’s leg to the wall. This is a severe limitation, but should vanish in the future with the advent of “wireless” chargers, where a device is connected to the 1Piece and charges it without needing an electrical outlet. Even today most of the vendors propose wireless charging.


  1. 2Piece

The 2Piece solution contains a GPS receiver carried by the subject on their bag or belt, along with a bracelet attached to the subject’s ankle with which it communicates by RF. The solution  can identify the GPS receiver unit’s location and communicate that through the cellular network (usually GSM).

One major difference between the 1Piece and 2Piece solutions is that the location of the unit is the same as the location of the subject in the former, whereas in 2Piece, it is only the location of the unit (the GPS receiver). With 2Piece, the subject is responsible for taking the GPS unit with them. This is not the case with 1Piece.

For 2Piece, communication must be maintained between the GPS and the RF unit at all times, as this indicates that the GPS unit is actually on the subject. 2Piece allows more flexibility in the design of the GPS unit as it’s not actually on the subject’s body. The GPS unit can operate similarly to a cell phone, with text or voice messages to communicate with the subject. There are new solutions today, which are using Cell phones as the GPS receiver for EM, since this solution contains all needed capabilities, like GSM communication, text messages and voice calls.

There is a slight difference in the installation process between installing the two solutions; the 1Piece only requires activating one device, whereas the 2Piece obviously needs two.

  1. Comparison between 1P and 2P
  • Co-operation of subject – 1P only requires subject co-operation for charging, while the 2P also requires the subject to carry the device with them. Disorganised subjects tend to have difficulty with 2P devices.
  • Communication with subject is more powerful using the 2P solution, which allows text messages and voice calls, whereas the 1P allows only more primitive communication like LEDs, vibrations and sounds. Implementation of the 2P solution in future will probably have the GPS unit in a cell phone.
  • Battery charging – until recently, the 2P had a significant subject’s mobility advantage here. However, with the new wireless charging, this advantage almost disappears.
  • GPS and cellular reception are better with the 2P because the unit is at waist rather than ankle level.

The 1P is usually cheaper and simpler than the 2P solution. Great consideration should be taken before neglecting 1P in favour of the more complex 2P.


EMiS-CON staff will be happy to assist and answer questions.