Improving communications with bluetooth enabled collaborative middleware in MANET

The Journal of China Universities of Posts and Telecommunications June 2012, 19(Suppl. 1): 100–107 www.sciencedirect.com/science/journal/10058885

http://jcupt.xsw.bupt.cn

Improving communications with bluetooth enabled collaborative middleware in MANET GAO Feng1 ( ), LIU Qi2, HOPE Martin3, FAN Tong-rang1 1. School of Information Science and Technology, Shijiazhuang Tiedao University, Shijiazhuang 050043, China 2. Jiangsu Engineering Center of Network Monitoring, Nanjing University of Information Science and Technology, Nanjing 210044, China 3. School of Computer Science and Engineering, the University of Salford Manchester, M5 4WT, UK

Abstract The main aim of the research presented in this paper was to investigate how can collaborative middleware based collaborative working environment (CWE), combined with bluetooth technology, enhance the communications of mobile users. The high level collaborative middleware is a research and technology development (RTD) challenge and a desirable research outputs for CWEs. This paper outlines a collaborative middleware that has been developed on smartphone technology and enables the creation of a multi-user CWE via a bluetooth network. To achieve this aim, it started with discussing the key design parameters, and then the design of collaborative middleware with collaborative functionality; ended by completed a strengths, weaknesses, opportunities, and threats (SWOT) analysis with focus group to determine the collaborative middleware’s potential impact to improve communications between users. The result of the evaluation concludes the bluetooth enabled collaborative middleware can improve the communications of mobile ad-hoc networks. This research also provides two key areas of contribution. Firstly it provides an evolutionary step for the creation of new collaborative applications. Secondly, it has optimised the use of bluetooth beyond the functionality for which it was originally designed. Keywords collaborative working environment, bluetooth, middleware

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Introduction 

The result of research activity in the field of mobile Ad-hoc networks (MANETs) has made short to medium range radio communication transceivers very popular and inexpensive. After some initial problems, bluetooth [1] today has become a very common feature on smartphones. Other wireless technologies, such as Zigbee [2], also take the advantage of low-power and cost-effective, however, it have not used on smartphones devices widely. In 2006, twelve research challenges [3] about CWEs were listed as RTD challenges by the European Commission. Within this list the two most desirable medium to long term research outputs were the development of a high level middleware called Upperware, and a reference model. At the initial Received date: 12-05-2012 Corresponding author: GAO Feng, E-mail: [email protected] DOI: 10.1016/S1005-8885(11)60461-5

stage of this research, this high level middleware became the focus which aimed at developing a middleware platform supporting a CWE on a mobile platform using bluetooth as a wireless networking technology [4]. This then gave rise to the research question: can collaborative middleware based CWE, combined with bluetooth technology, enhance the communications of mobile users? Collaborative working is a business term pertaining to a method of working in which people at different locations or from different organizations work together electronically using videoconferencing, e-mail, networks, and other communication tools [4]. The communication tools support people in their individual and cooperative work. The environment built by these communication tools is called a CWE [5]. In this paper, the term CWEs and collaborative environments are indistinct; both of them refer to systems that enable human oriented collaboration.

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The purpose of the collaborative can then be for work or leisure, depending on the particular setting. A MANET is a self-configuring system of mobile nodes connected together by wireless links. In a MANET, the nodes are free to move randomly, changing the network’s topology rapidly and unpredictably. MANETs are decentralized, and therefore all network activities are carried out by the nodes themselves [3]. There are several wireless technologies available to setup MANETs, such as Wi-Fi, bluetooth and radio frequency (RF) system [5]. In recent years bluetooth has become very popular in most mobile devices such as personal digital assistant (PDA), laptops and mobile phones. Although bluetooth as a technology has its own limitations, as a short range mobile ad-hoc network research on bluetooth has not been exhausted. The research presented in this paper outlines a collaborative middleware that has been developed on smartphone technology and enables the creation of a multi-user CWE via a bluetooth wireless communications network. This collaborative middleware not only provides a step for the creation of new collaborative applications, but it has also optimised the use of bluetooth beyond the functionality for which it was originally designed for replacing cable. The aim of the evaluation for this research was to seek an understanding of the ranges of response to this form of new technology, and to understand some of the ways that the users can appreciate its potential. Therefore, key to the analysis is the search for qualitative inputs to give indications of the types and kinds of issues which users and others may regards as important [5]. The research used two forms of data collection. Verbal response from participants during a demonstration of the technology and in answer to an agreed set of questions: participants were asked for their initial reactions and for questions they have about the collaborative middleware. Participants were also asked to compare and contrast the collaborative application approach with existing ways of sending data and for their preferences about each approach. Written responses to a set of questions were asked after the demonstration was completed. Participants were then asked to undertake a SWOT analysis with regard to the collaborative middleware. Supplementary questions were also asked in terms of suggestions to improve weaknesses and ways to overcome concerns about threatening issues [6]. The SWOT analysis traditionally examines how

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the threats and opportunities can be dealt with Ref. [7], while allowing the organization to meet its key success factors. These should be concise, brief and specific indicators to key and important issues. Basic SWOT analysis should discuss, illustrate and debate the potential strengths, weaknesses, opportunities and threats identified, with how the collaborative middleware can build on its strengths, exploit opportunities and minimise the threats and weaknesses within the middleware. The research has made a contribution to knowledge in the specific area of collaborative middleware for MANETs using bluetooth as a communications technology on a smartphone platform in particular with a view to enhancing communications. As previously mentioned the collaborative middleware resides on a smartphone operating system (OS) and provides an interface for collaborative applications using a bluetooth network. CWE applications were initially designed for the desktop computer using wired networks; however, smartphones with personal computer (PC)-like functionality can also deal with some light-weight functionality in CWEs [8]. Particularly given that the performance, processing power and memory are continually increasing on modern devices. The developed middleware encapsulates the functionality of CWE applications into a set of classes which can be reused for developing collaborative applications that require distribution via a bluetooth network. The functionality of the collaborative application could support point to point communication and group based communications, such as group member management, group message, and file transfer within a group. This is a unique contribution and has brought the potential of CWEs to mobile devices via bluetooth. The developed middleware uses bluetooth communication technology to maintain a MANET for a CWE. This is beyond the initial design purpose of bluetooth which aimed at replacing the myriad of data cables normally associated with computer peripherals [9]. The normal use of bluetooth on a mobile phone is to transmit chunks of data, such as pictures or music, based on peer to peer network topology [10]. In this kind of scenario, bluetooth is just a replacement of the data cables normally required. In this research, the usage of bluetooth technology on a smartphone platform has been extended to maintain a MANET for the sole purpose of developing a CWE. To the authors knowledge this is a unique

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application of bluetooth communications technology and can be considered a unique contribution.

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Middleware design

There are three related layers in the architecture of the collaborative template (Fig. 1): the network layer, the collaboration management layer and the application layer. The database store data for the collaboration management layer. There are four function modules in the collaboration management layer: device and service discovery module, device and service control module, group communication module and routing module. In this paper, the device and service discovery module and group communication module are discussed, the other two modules are based on the Symbian OS and bluetooth hardware, which are over the scope of this paper.

Fig. 1 The architecture of the collaborative middleware

2.1 Device and service discovery In order to set up a collaborative bluetooth network, the first thing to consider is how to establish and maintain a bluetooth network. Functional classes were considered as access points for the application. There are three stages involved in bluetooth communications using a socket: device discovery, service discovery, and the communication itself [11]. Based on these stages a state machine model was developed as a design for the set-up of the bluetooth network. The application state starts from BTDormant, which is waiting for a user or client to request bluetooth communications. When a user requests a connection, the application then searches for devices within range, the state is BTDiscoveringDevices. If the application has not found any devices, the user can then restart the device discovery process; otherwise, the master is searching for the required service on each of the discovered devices. If no required services are found, the

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user can re-start the device discovery. After initiating a connection with a slave, and the master has established a connection with the server, the state is then BTWaitingToSend. When the master receives an enquiry message from the slave, the state then changes to BTWaitingToReceive. The bluetooth network can then be set up following these processes. 2.2 Group communications module Group communications is a primary function of a CWE. It provides the foundation for user collaboration and thus requires an accessible communications network. There are two scenarios for group communications via a bluetooth network: 1) group member devices connected; 2) group member devices not connected In the first scenario, all group member devices have finished device and service discovery. Under these conditions, the master can send data to all connected slaves. Thus from a CWE context, the group leader can send data to all group members or select from those connected whom to send information to. When data is sent from any of the slave devices, the data will first be sent to the master who then echoes it to the other slaves. In group communications, if the members of the group are already determined and the communications between the members are frequently. Then users within the group may already know the destinations device and services that are available. Hence, if the source device has already saved the destinations address, it can potentially skip the process of device and service discovery, and send data to the destination directly. In this case, a database is needed for store the regular destinations’ MAC address and other details. 2.3 Key design issue In the last two sections, some functional middleware design plans are presented. This highlights a profile of the middleware for a CWE on a bluetooth network which consists of a set of classes in order to control the bluetooth network communications and support interfaces for applications to take user commands. If we think about implementation at this stage, a design issue can be anticipated. The bluetooth network can be controlled by different application programming interfaces (APIs) depending on the implementation platform (e.g. S60, UIQ) and should

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not be an issue for implementation. However, there are too many member functions related to bluetooth operation. In order to make these classes work better, a ControlBT class is required for the middleware, which can control most of the classes and support an interface to the applications. The application then only needs to call the ControlBT class whilst the other functional classes remain transparent to the applications. The middleware is made up by a set of classes. These classes invoke APIs to control hardware and supply member functions to applications. In the chat module, a point to multipoint communication capability was designed to invoke a number of bluetooth APIs. Device discovery seeks bluetooth devices within range and service discovery searches for the services other bluetooth devices offer, it then filters the service discovery query in order to return only the service class required. In this way, the service discovery query will only return the service entries that match the service class of our service, which will save the time of service discovery. A connection will then be established to all the remote bluetooth devices found to be offering the service we require. Once the connections are established, messages can be sent from the master device to the connected slaves, and vice versa, from a slave to its master. All these processes can be transparent to the applications residing above the middleware by using the SendData() member function in the ControlBT class.

3

Test strategy

After a careful review of the available mobile operating systems; the Symbian OS was chosen as the platform for the middleware implementation. The Symbian OS is preferred over many others because it is an open system that supplies a software development kit (SDK) to its developers. Symbian OS applications are created by the development of a user interface (UI) and an applications engine. In the latter, the software architecture of the applications engine is very similar in concept to that of generic middleware and presents an ideal development scenario. 3.1

Test overview

An eight member focus group was held for testing the middleware. Eight Nokia smartphones were used for testing, including two Nokia E50s, two Nokia N73s, two Nokia N95s and two Nokia 6120s. It should be noted that

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all testing activities were limited to one piconet where one smartphone was labeled the master, and the others were labeled from A to G randomly. The testing started with a practical demonstration of collaborative applications which supported by the collaborative middleware, and then all participants carried out the testing scenario in order to evaluate the middleware with a view enhancing the use of bluetooth and methods of collaborative working. Finally, a questionnaire was answered by all members of the group. 3.2 Data collection As mentioned in Sect. 1, verbal responses and written responses are the two methods of data collection outlined during and after the testing process. The participants were asked the following set of questions: 1) What are your initial reactions to what you have seen? 2) What questions do you have? 3) How satisfied would you be in using these applications? On a scale of 1-10 (where 10 is very confident). 4) How would the work you do be different with something like this? 5) How does this compare with the existing way of doing things? The questions were asked in a formal manner after a general discussion of the applications under test. All participants were asked the same questions in the same order. Justification for asking these particular questions is self-evident in that the main focus of the testing was to elicit the participants’ perception of how this middleware may improve or deter current ways of collaborative working on bluetooth network. In addition, an attempt was made to determine a level of confidence associated with the use of the software application so that a degree of potential resistance to change and the new applications based on middleware could be gauged. The answer to each question from each participant was noted during the testing. Having completed the testing scenario, willing participants were then asked to complete a SWOT questionnaire (Fig. 2). This questionnaire considered the strengths, weaknesses, opportunities and threats associated with the middleware and a comparison between the two methods of working (with or without applications). The comparison test made the participants do the same tasks in two scenarios with OS

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default interface, and then comparing to the scenario with collaborative application for same tasks. SWOT QUESTIONAIRE NAME Q1.1 Think for a moment about how the applications you have seen demonstrated and tested compares with the previous way of using Bluetooth on Smartphone. Please write in the boxes below any Strengths, Weaknesses, Opportunities or Threats that occur to you when you are comparing the two ways of doing things. Strengths

Weaknesses

Threats

Opportunities

Q1.2 For each of the weaknesses can you suggest what is needed to improve it. Q 1.3 For each of the threats please suggest an approach which would overcome your concerns. Q1.4 How might these application be useful to you in your work?

Fig. 2

Having constructed the SWOT matrix for both questionnaires the subsequent analyses presented in next section aims to minimize the weaknesses and threats, and maximize the strengths and opportunities by considering the following classic strategies: 1) S-O strategies aim to develop the strengths in order to pursue related opportunities. 2) W-O strategies aim to overcome the weaknesses to in order pursue opportunities. 3) S-T strategies identify ways that the prototype system can use its strengths to reduce its vulnerability to external threats. 4) W-T strategies establish a defensive plan to prevent the prototype systems weaknesses from making it highly susceptible to external threats.

SWOT questionnaire

As previously mentioned, SWOT questionnaires were presented to the participants after testing a set of scenarios, the main purpose of which was to consider a comparison of two methods of using a bluetooth network to collaboratively work. Although traditionally a SWOT analysis considers the view point of one person, a slightly different approach was adopted here, in that the analyses presented in the page before for the questionnaires considers the view point of many people that when combined and categorized, presents a majority opinion. In general, the view points of the participants were particularly diverse, and a pluralistic approach could have been adopted in order to extract conclusions from the data. However, when considering the data in more detail it was found that synergy between different participant’s results existed and these were categorized under different headings. In an attempt to rank the most frequently occurring results and thus the most important parameters a simple weighting (0-10 representing 0-100% of respondents) was also applied to each category. This is shown in Table 1 as a number in square brackets to the right of each category. In order to efficiently analyze the data, identify key concepts, and develop strategies that highlight the potential of the system to further improve remote working practices, a SWOT matrix (also known as a TOWS matrix) was constructed and is shown in template form in Table 1.

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Results and evaluation

Fig. 4 outlines the combined and categorized results of the SWOT questionnaires presented to the participants after the practical demonstration of the collaborative applications and the comparison tests. The tests considered a comparison of the two methods of data transfer (with and without the collaborative applications). It should be noted that for ease of reference, the strengths, weaknesses, opportunities, and threats have been ranked in order and labelled accordingly. For example, the strength labeled S1 in Fig. 4. (A saving in device discovery time [7]) is the highest ranking strength with 86% of respondents making this particular comment. Strengths . A saving in device discovery time [6]. .New functions for using bluetooth on smartphone [5]. .Alternative of text message in some scenarios [4]. .Useful for group work[3]. .Easy to use[2]. Threats .Data security [5]. .Mobile phone easily lost [5]. .Wi-Fi and 3G networks [3]. .Other collaborative applications [2].

Fig. 3 Table 1 Opportunities Threats

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Weaknesses .Only works on Symbian OS [6]. .No log Record [5]. .Training [4]. .No graphic interface [2].

Opportunities .To support other mobile OS [6]. .To support other networks (3G or Wi-Fi)[5]. .To support multiplayer game [4]. .To focus on business users [2]. .To support web server for more functions [1].

SWOT results

SWOT matrix

Strengths S-O strategies S-T strategies

Weaknesses W-O strategies W-T strategies

4.1

S-O strategies

The highest ranking strength perceived by the

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participants completing the SWOT questionnaire was that of a saving in device discovery time S1. Obviously to build on this strength the main opportunity presented in Fig. 3 would be to further support other mobile operating systems. As discussed in chapter five, it is possible for the collaborative middleware to support other mobile operating system. The easiest way to realise this, is to re-compile all classes into a dynamic link ibrary (DLL), mainly because most of mobile phone’s SDKs support the invocation of DLL files. The second highest ranking categorized in the opportunities , was the support for other networks. However, whilst this is feasible, it is not directly inline with the research objectives since the key focus was on the bluetooth network and the CWE the middleware implementation presented. Another high ranking strength was the new functionality the middleware presented for using bluetooth on a smartphone platform . One of the key functions here was sending text messages between group members, . This is an essential part of a collaborative environment and although this functionality is not unique to this research activity; to the author’s knowledge, this is the first time it has been deployed over a bluetooth network. This specific contribution is also reflected in . In addition, based on and , and to focus on the business user, provides a great opportunity for the collaborative middleware. This is because a mobile CWE is very suitable to small sized group meetings or working groups. In addition, given that the coverage range of bluetooth can now extend up to one hundred metres, and with the new features becoming available in the new standard (version 3.0); bluetooth is fast becoming a competitive alternative to other networking technologies such as Wi-Fi, particularly when combined with other advantages such as low cost, ease of use, and in particular it’s ubiquity. The capacity to support web server access for more functionality is a current trend for mobile phone applications. Many mobile phone applications such as the ‘iPhone Apps’ can connect to a web server via a 3G or Wi-Fi Internet connection. However, whilst it is feasible for future work, the network structure of bluetooth was designed for short range and occasional connection, and is not suitable for Internet connectivity. 4.2 W-O strategies The highest ranking weakness perceived by the

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participants was the limitation of the OS . Comments from the participants particularly focused on the Symbian OS which was considered a limited implementation with regard to the availability of other smartphone OSs. From the author’s perspective this is a relatively abstract concept in that the CWE system was aimed at providing a test bed for further research and not as a final solution for deployment. In contrast, and from the participant’s point of view, Symbian OS is not the only OS for smartphones and the middleware should support other mobile OS, . This point of view is not without credibility, since the market share for the smartphone is always changing, and the Symbian OS was not in the leading position of the smartphone market since 2009. The second ranking weakness outlined in Fig. 3 was the lack of a log record . This was a justifiable criticism from the participants; however, given that the collaborative applications were developed for testing only, the middleware did not have the functionality to record all information, such as transmission and communication history. However, for future work, if the middleware was to focus on the business user, and was further developed as a commercial application, a record of this type of information would be an essential part of the collaborative application. The third ranking weakness for the collaborative applications outlined in Fig. 3 was that of ‘Training’ W3. Here, the participants thought that users of the system would require training before using the collaborative applications. In addition to training, the final weakness was ‘no graphical interface’. Both of these issues were related to the users’ experience and reflected upon the fact that the collaborative application was not easy to use. It was highlighted that training would be required for users without a networking background, were the topology of the bluetooth network would be the key focus of the training. It is also anticipated that using a graphic interface would a good approach to reducing the training workload, as most users would learn the functionality of the program through visual imagery. 4.3

S-T strategies

The key threats to the collaborative middleware in Fig. 3 were the security of both data , and devices . This included access to data over the bluetooth network by outside parties, the corruption of data by inexperienced

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users updating files, and the loss of devices due to theft in the office place, or from the smartphone being lost during daily life. The security of data and device would also be directly linked with costs, since both would have to be immediately replaced to keep the CWE working. Obviously the security of both data and equipment would be of paramount importance to the users or organisation. From a network perspective, the bluetooth security is divided into three modes: 1) non-secure; 2) service level enforced security; and 3) link level enforced security [12]. The manufacturer of each product determines these security modes. Devices and services have different security levels. For devices, there are two levels: "trusted device" and "untrusted device." Here a trusted device is a device that has been paired with one of the other devices which then has unrestricted access to all services. However, there are still some security risks for bluetooth networks, such as bluejacking, bluesnarfing and the Cabir worm. bluejacking is the process of sending unsolicited messages, or business cards, to bluetooth-enabled devices. This does not involve altering any data from the device, but nonetheless, it is unsolicited. bluesnarfing is a method of getting access to a bluetooth-enabled mobile phone and copying its entire contacts book, calendar or anything else stored in the phone’s memory. However, since 2006 companies such as Nokia and Sony Ericsson have been developing mobile phones that are not be susceptible to bluesnarfing [13]. The Cabir worm on the other and is a malicious piece of software that uses bluetooth technology to seek out other available bluetooth devices and it then sends itself to them. The Carbir worm currently only affects mobile phones that use the Symbain series 60 user interfaces that incorporate bluetooth wireless technology. Furthermore, the user has to manually accept the worm and install the malware in order to infect the phone. Although this is an unlikely scenario, where users knowingly infect their mobile phones, it does highlight the possibility that mobile viruses can spread via bluetooth which may prompt other developers to explore the possibilities of writing other bluetooth based viruses. Therefore, the CWE users should be trained and be familiar with bluetooth security issues before using bluetooth devices, especially before they bring devices for use in the work place. Other types of network and applications were also considered a threat to the further development of the collaborative middleware and are highlighted in and

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. Although Wi-Fi and 3G networks have their advantages, the bluetooth module is already an essential component embedded in the majority of mobile phones and in all smartphones. Thus, when combined with the other advantages of the bluetooth network, a CWE based on a bluetooth platform can be potentially a better solution than other network technologies. 4.4 W-T strategies This final sub-section aims to establish a defensive plan that prevents the collaborative middleware’s weakness from making it susceptible to the external threats. Key to this analysis is security, and the direct correlation between , and . As previous mentioned the main perception by participants was that of data and device security and user training. From Sect. 4.3 a S-T strategy suggested that user training could reduce the risk of security issues. The limitation of the OS, , can also be linked to the threat from other collaborative applications . However, the aim of research focus on enhancing communications of bluetooth network by collaborative middleware; other application could be as reference for this project, not as threat. 4.5 A summary of key strategies The following provides a summary of key strategies derived from the analysis of the SWOT questionnaires in previous section. 1) Provide user instructions for the collaborative applications as a training guide. 2) Consider the addition of a function to support the logging of records. 3) Compile the classes into dynamic link library in order to support other mobile operating systems. 4) Provide a user authentication function to prevent data lose in the case of device theft. 5) Review data security issues for bluetooth networks. 6) Consider the adoption of alternative cellular network technologies and other wireless communication networks. 7) Consider the development of a graphic interface as an improvement to the user interface of the collaborative applications. 8) Further review other CWE on other mobile platforms.

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Conclusions

The design and implementation of the collaborative middleware has achieved the aims set out in Sect. 1. It has supported the development of a CWE in a MANET using Bluetooth communications technology based on a smartphone platform. It has also provided a set of reusable functions that are available to higher level applications which are transparent to both application developers and users. All key objectives have also been achieved. A conceptual model that can be used to represent collaborative middleware included three layers: the network layer, the collaboration management layer and the application layer. The collaboration management layer control network layer and support collaborative functions to application layer. A database was designed to supply database service for the collaboration management layer, such as current connected list, trusted address, and recent connected address. The middleware was implemented on the Symbian OS S60 3rd edition platform, which was running as an application engine to supply interfaces for applications. Three collaborative applications based on in this application engine were developed and tested on the devices, which were also evaluated by a focus group by a comparison test and a SWOT questionnaire. The results of the comparison test clearly reflected the time difference between using the collaborative application or the Symbian OS bluetooth interface in order to finish a number of device discovery and connection tasks. The collaborative application not only can save time to finish the same task, but also provides higher stability than the Symbian OS bluetooth interface. The results of the SWOT questionnaire had been analysis by a SWOT matrix to maximise the strength and opportunities and minimise the weakness and threats of the collaborative middleware. This research successfully achieved the research aims. The middleware of CWE is one of most desirable research prospective of CWE, this research made the middleware available on smartphone platform via bluetooth network.

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This research also extended the use of bluetooth to support CWE’s which is beyond the initial design of bluetooth, which was to replace cables between devices. Acknowledgements This work was supported by the Natural Science Foundation of Hebei Province (F2009000927).

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