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TOPICS IN CONSUMER COMMUNICATIONS AND NETWORKING

Trends in Entertainment, Home Automation and e-Health: Toward Cross-Domain Integration

Antonio Aragüés, Ignacio Martínez, Pilar del Valle, Pilar Muñoz, Javier Escayola, and Jesús D. Trigo, University Zaragoza (UZ)

ABSTRACT The field of communications has witnessed the simultaneous spread of numerous general-pur- Recent advances in consumer networking and pose, low-power, and close-proximity technolo- emerging technologies are promoting a paradigm gies, such as Wi-Fi, WUSB, Bluetooth, ZigBee, or shift in the way environments such as entertain- NFC, to name only a few. Such technologies are ment, home automation or e-Health are tradi- crucial in the development of new consumer ser- tionally understood. However, available vices. However, despite their success, the wireless technologies present different characteristics communication technologies arena is a convolut- depending on the environment or the working ed and segmented ecosystem (Fig. 1). The avail- domain that, in a context of non-experienced able technologies present different characteristics users, hinders the development of interoperable depending on the environment or the working services. This article compares the most recent domain. In a context of non-experienced users, technological proposals and analyzes their key such heterogeneity hinders the development of points, and presents a compilation of the major interoperable services [1]. interoperability proposals and initiatives for the In an attempt to seamlessly handle this het- considered communication domains. The work is erogeneity in the aforementioned domains, sev- completed with a reasoned discussion on trends eral higher-layer interoperability protocol stacks on architectural approaches to cross-domain and services have emerged, such as DLNA for integration that can be used to overcome the entertainment, several ZigBee profiles for home issues generated by the segmented ecosystems automation, or different interoperability stan- presented above. dards for e-Health [2]. However, these efforts lack cross-domain initiatives that enable integra- INTRODUCTION tion of the above-mentioned consumer domains in order to build the longed-for smart home. Recent advances in consumer networking and To achieve such a goal therefore required the emerging technologies are promoting a paradigm design of novel abstraction-based architectures shift in the way environments such as entertain- that facilitate the path toward the integration of ment, home automation, or e-Health are tradi- different scenarios in a single framework. Some tionally understood. The latest products in proposals — based on different approaches — can consumer electronics — such as smartphones, be found in the literature [3]-[8]. The two prevail- tablets, smart televisions, medical devices, etc. — ing styles for distributed systems include: Service are empowering users to custom shape a smart Oriented Architectures (SOA) and Resource Ori- home, in which their spare time, domotics, or ented Architectures (ROA) that, at the same time, health can be intelligently managed. Such envi- make use of other closely-related concepts such as ronments have different technological require- “Web of Things,” Web Services (WS), or Physical ments, depending on their specific features: the Mashups. An appropriate combination of tech- entertainment domain requires high bandwidth, nologies and interoperability initiatives as well as streaming capabilities, real time and low latency; the selection of a suitable architecture is required the home automation domain requires low- if a full fledged, smart home that enables cross- power and small sensors; and the e-Health domain integration aims to be achieved. domain requires high security, univocal measure- The objectives of this article are: patient match and ubiquitous capabilities. Cross- • To review and compare the main consumer domain solutions are being applied in communication technologies that can be unconventional ways to provide novel platforms applied in home environments such as where interoperation between heterogeneous entertainment, home automation or technologies begins to be possible. e-Health.

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• To present a sorted compilation of the major interoperability proposals and initia- Home automation tives for the aforementioned domains. • To perform a reasoned discussion on trends

TANDARD TY S S A on architectural approaches for cross- ILI ND AB IN ER IT P IA O T R IV E E T domain integration that can be used to General purpose S N I overcome the issues generated by the seg- Low power Close proximity mented ecosystems presented above. Technologies C R O N S IO The conclusions are then drawn. S AT -DO R MAIN INTEG

EMERGING WIRELESS

TECHNOLOGIES FOR Entertainment E-health CONSUMER NETWORKING Figure 1. Scheme of wireless communication technologies arena for consumer This section compares the most recent emerging networking at home. wireless technologies for consumer networking, analyzing their key points. Technologies can be categorized based on several aspects. The pro- technology that features simple design, low posed review distinguishes two main groups: the latency, high resource optimization, network most spread technologies (subdivided according flexibility and scalability, ease of use with low- to their main features into general-purpose, cost systems, very high transfer rate (e.g. ANT close-proximity, and low-power) and particular stays on air four times less than ZigBee to trans- initiatives for each one of the communications mit a given volume of data) and optimized bat- environments previously introduced: entertain- tery life (e.g., with a consumption of 24 ment, home automation and e-health. It is worth hours/day and seven days/week, ANT works up noting that the technologies included in the first to three years, ZigBee up to six months and group could be applied to any of the environ- Bluetooth up to seven days). Z-Wave is a propri- ments of the second group. For every technolo- etary protocol based on low-power consumption gy, an extended technological study can be found RF embedded technology with highly optimized in [2] and the technical information within the headers for reliable and low-latency communica- recommended scenarios are shown in Fig. 1 and tion of small data packets, unlike Wi-Fi systems detailed in Table 1. that are designed primarily for high-bandwidth The first group comprises general-purpose data flow. DASH7, based on ISO/IEC 18000-7 (i.e., not designed for a specific domain) tech- and re-oriented from military purposes to com- nologies such as Wi-Fi, Bluetooth, ZigBee, and mercial applications as an alternative to propri- WUSB. The IEEE 802.11 family of standards, etary protocols like ZigBee or Z-Wave, features commercialized under the Wi-Fi trademark, has ultra-low-power consumption (10 times less than evolved through different versions, 802.11a/b/g/n, ZigBee), high coverage ranges (six times more to the most recent 802.11ac, currently under than ZigBee) and multi-year battery life, low development, which enables multi-station latency in object location, encryption and WLAN by using wider radio bandwidth, up to reduced protocol stack. 6LoWPAN, defined by eight streams and high-density modulation. Blue- IETF and oriented toward embedded devices, tooth has also released several versions, such as features Internet Protocol (IP) connectivity with BT2.1+EDR, BT3.0+HS, and the most recent a simple header frame design and a hierarchical BT4.0 or BTLE available in some high-end addressing model that, similar to DASH7 and smartphones and featuring ultra-low-power con- unlike ZigBee, guarantees the interoperability sumption idle operation mode (several times less among IP-based devices that enables building than conventional Bluetooth devices), low laten- the wireless “Web of Things,” as will be dis- cy, simple device discovery service and faster cussed later. transfer speeds. Bluetooth and Wi-Fi have some The third group consists of close-proximity similar applications as they are considered the technologies such as NFC and TransferJet. NFC, replacement for cabling: Bluetooth for portable based on RF identification (RFID) standards equipment and Wi-Fi for general WLAN (high- including ISO/IEC18092 and ECMA340, fea- power consumption). ZigBee, operating on the tures fast data transfer with reduced payload, IEEE 802.15.4 radio standard, is focused on quick connection set-up (about 1s) and low cov- embedded applications requiring low data rates, erage (can work up till a few centimeters) as it low-power consumption and a considerably sim- uses magnetic fields as media. TransferJet is a pler and cheaper hardware than Bluetooth (bat- new close-proximity wireless technology featur- tery life lasts 30 times longer). WUSB is a ing simple operation by just approaching two short-range and high-bandwidth wireless proto- devices, such as automatically initiating a P2P col — based on the emerging UWB radio tech- content transfer, that allows, as with NFC, high- nology — that features extensive bandwidth, speed data exchange. However, TransferJet is improved power efficiency, proximity-based asso- intended to replace USB cables for massive file ciation mechanism and wired-like security. transfer at super-fast speeds, while NFC is The second group, which includes some of intended to securely send and receive small-data the previous options, covers low-power technolo- transactions. gies such as ANT, Z-Wave, DASH7, and 6LoW- The fourth group is focused on specific tech- PAN. ANT is a proprietary ultra-low-power nologies for entertainment (such as WHDI,

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General Low-Power Close- Entertain- Home Automation e- Purpose prox. ment Health Wi-Fi Bluetooth ANT Z-Wave DASH7 TransferJet WiHD RuBee X10 EnOcean Sensium Zarlink ZigBee WUSB 6LowPAN WHDI WiGig NFC LonWorks KNX

Telecommunication devices • (routers)

High-definition multimedia • • • solutions

Remote control for home • • • • • • • • automation Scenarios Connectivity of medical devices • • • • •

Wireless Sensor Networks (WSN) • • • • • • • • •

Embedded systems • • • • • • • • • •

Smart-energy based systems • • • • • • • • • •

IP-connectivity supported solutions • • • •

Point-to-Point (P2P) • • • • • • • • • •

Topology Mesh • • • • • • • • •

Star (master-slave) • • •

Several centimeters • •

Cover Several meters • • • • • • • • • range Up to 100m • • • • •

More than 100m • • •

Several b/s •

Several kb/s • • •

Maximum Up to 250kb/s • • • • • data rate Several Mb/s • • • •

Up to 450Mb/s • • •

More than 1Gb/s • • • •

Ultra-low-power consumption • • • • • •

Power Low-power consumption • • • • • • •

Standard power consumption • • • • • • • • •

120–130kHz

13.56MHz •

433MHz • • RF band 868–915MHz • • • • • •

2.4GHz • • • •

More than 2.4GHz • • • • • • •

Alliance, Special Interest Group • • • • • • • • • • • • (SIG) Entities, bodies Standard (IEEE, ISO, IETF) • • • • • • •

Proprietary • • • • • Table 1. Comparative study of proposed emerging technologies for entertainment, home automation and e-Health.

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Cross-domain interoperability

Entertainment Home automation e-Health ISO/IEEE 11073 UPnP IEEE 1451 (ISO/IEC 29341) HL7 HC Interoperability WiFi HDP ANT+ DLNA direct PHDC 6LoWPAN Profiles Profiles Profiles WiHD WHDI WiGig Zarlink Wi-Fi Lonworks KNX Sensium USB X10 ANT ZigBee ZigBee RuBee EnOcean ZigBee Bluetooth Bluetooth

WUSB Z-Wave DASH7 NFC TransferJet Technologies

Figure 2. Conceptual scheme of cross-domain integration for consumer electronics, home automation and e-Health.

WiHD and WiGig), home automation (such as is required. The IEEE definition of interoper- LonWorks, RuBee, X10, KNX and EnOcean) ability is “the ability of two or more systems or and e-Health (such as Sensium and Zarlink). components to exchange information and to use LonWorks is a proprietary networking platform the information that has been exchanged” [1]. over ISO/IEC 14908-1 that addresses control of Even though this abstract statement seems easily home applications over several media such as achievable, after looking at the previous technol- RF and twisted pair, power-lines or fiber optics. ogy snapshot it becomes a harder milestone and RuBee, supported by IEEE 1902.1, defines the is still far from being completely implemented. air interface for radiating transceiver radio tags, In addition, even though two devices are con- using long wavelength signals and very-low- nected using the same technology, it is not a triv- power consumption devices, and fills a gap ial task to enable them to interoperate without between non-network-based RFID standards the proper communication protocol so that an and existing high-bandwidth network standards application-interoperability solution context is such as IEEE 802.11 and IEEE 802.15.4. X10 is needed. an international and open industry standard for Historically, depending on the desired level electronic device communication that uses of integration and application extension among power-line wiring for signaling and handling con- other devices, this adaptation level can be pro- trol, where the signals involve short RF bursts prietary or “standard” within the same technolo- representing digital information, and defines a gy (e.g., Bluetooth has adopted plenty of wireless radio protocol. KNX, developed by proprietary applications based on Serial Port EN 50090 and ISO/IEC 14543, is an OSI-based Profile (SPP), which would be considered as a network protocol for intelligent buildings that proprietary approach, while the definition of groups three previous standards leveraging the profiles, which, in fact, SPP belongs to, provides EIB communication stack with extended physical context-oriented integration mechanisms, and layers, configuration modes and the application this example can be extended to USB or Zig- experience of BatiBUS and EHS. EnOcean is a Bee). Thus, technology manufacturers have been German wireless technology based on the con- developing proprietary solutions on top of these cepts of energy harvesting, energetically efficient communication technologies so that a proper exploitation of applied slight mechanical excita- system functioning in a well-known scenario can tion and other potentials from the environment be guaranteed, and Standard Developing Orga- that avoids the need for EnOcean products to nizations (SDO), such as IEEE, IETF, ISO, use a battery to operate. IEC, etc., have supported this development by providing the necessary standard interoperability tools. In this context, a compilation of the major INTEROPERABILITY PROPOSALS AND interoperability proposals and initiatives for the INITIATIVES FOR WIRELESS three considered domains is detailed in Fig. 2. CONSUMER TECHNOLOGIES ENTERTAINMENT Wi-Fi offers interoperability through communi- As it has been previously presented, the majority cation technologies such as DLNA and Wi-Fi of the technologies developed for enabling com- Direct: DLNA allows devices to share and munications have been designed as application/ stream content over an existing wired/wireless domain independent. That is, they provide a set network while high level applications are also of features that may suit specific requirements possible through Plug-and-Play (PnP) for service for an application or the related hardware imple- discovery; and Wi-Fi Direct allows devices to mentation, but are not defined to meet them connect directly by building their own wireless beforehand. Thus, in order to enable two devices network unlike a conventional access point con- or applications to seamlessly interact, an interop- figuration. Bluetooth and ZigBee enable inter- erability or domain-dependent application layer operability by defining application-context

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profiles: for Bluetooth, Advanced Audio Distri- through the full OSI reference model and, spe- The appearance of bution Profile (A2DP), Audio/Video Remote cially integrated with ISO/IEEE 11073, provides Control Profile (AVRCP), Video Distribution a mechanism for connecting to external health the “Web of Things” Profile (VDP), Headset Profile (HSP), Generic information systems. ANT+ is a top-level inter- paradigm, led by the Audio/Video Distribution Profile (GAVDP), operability layer that ensures compatibility emerging 6LoWPAN Basic Imaging Profile (BIP), and Basic Printing through ANT+ profiles, by defining specific net- Profile (BPP), among others; and for ZigBee, work parameters and data structure, so that and Internet-based Input Device, 3D Sync, Telecom Services, Net- ANT products from different manufacturers can technologies, work Devices, and Gateway, among others. communicate seamlessly. Sensium is a propri- WHDI enables wireless delivery of uncom- etary solution that defines a full protocol stack proposes a new pressed High-Definition Television (HDTV) for enabling a wireless system for vital sign mon- integration level, not throughout the home in a homogenous way (Wi- itoring featuring low-power consumption where only for the network Fi requires its DLNA interoperability layer) and each device specialization is integrated as a provides consistent picture quality equivalent to module, such as heart rate, temperature, etc., up (the previous wired HD Multimedia Interface (HDMI) cable, to 16 nodes. Zarlink is a proprietary solution “Internet of Things” low latency, multi-room availability, and low- that defines a full protocol stack system com- power consumption. WiHD allows uncompressed posed of an implantable RF transmitter for vision), but also digital transmission of HD audio/video (Wi-Fi ultra-low-power consumption in accordance with for the web. must rely on compression technologies), making the Medical Device Radio Communications Ser- it equivalent to a wireless HDMI but potentially vice (MedRadio). adapted for portable devices, and high transfer At this point, it has been shown that enabling rate (double that of WHDI). WiGig, with its interoperability by means of defining application recent certification-ready specification, will allow layers, introduces an additional fragmentation tri-band devices to wirelessly communicate at over the same communication technology lying multi-gigabit speeds (seven times faster than at lower layers. A first approach at attempting to 802.11ac and 10 times faster than 802.11n, while enable cross-domain integration involves estab- maintaining compatibility with existing Wi-Fi lishing a homogeneous layer just before the devices) enabling high performance wireless application level in order to expose a common data, display, and audio applications. interface for the information exchange process. Although this may seem a direct implementation HOME AUTOMATION of a protocol shim layer for adaptation, the Bluetooth has no specific application profiles for underlying technology layers and their architec- this domain, so most systems implement SPP, ture must therefore be considered. Both stan- leaving an upper layer to be completed. ZigBee dard and proprietary protocols are differentiated defines some profiles for this domain, such as in terms of the integration level relating to the Building Automation (efficient commercial OSI reference model, with some of them applied spaces), Remote Control (advanced remote con- to lower layers (IEEE 802.3, IEEE 802.11, ANT, trols), Smart Energy (home energy savings), Bluetooth, ZigBee), upper layers (Extensible Home Automation (smart homes), or Light Link Messaging and Presence Protocol (XMPP), (LED lighting control), among others. IEEE ISO/IEEE 11073 Personal Health Devices, 1451 establishes a set of standard interfaces that ANT+, WiGig Protocol Adaptation Layers describe common, network-independent commu- (PAL), Bluetooth/ZigBee profiles) or the com- nication interfaces for connecting transducers plete stack (ISO/IEEE 11073 Point-of-Care, and smart sensors to microprocessors. UPnP Digital Imaging and Communication in Medicine (ISO/IEC 29341) defines a set of upper-layer (DICOM), DLNA), as will be discussed in Sec- networking protocols to enable interoperability tion IV. among networked devices, and seamlessly dis- cover and establish functional network services. TRENDS AND CHALLENGES E-HEALTH OWARDS ROSS OMAIN ISO/IEEE 11073, developed by IEEE/ISO and T C -D CEN/CENELEC and promoted by Continua INTEGRATION Health Alliance and Integrating the Healthcare, defines a suite of full protocol stack for the In an attempt to achieve value-added solutions interoperable communication of medical devices in distributed networking scenarios such as home in higher layers, being transport-layer portable in environments and using the technologies and order to allow adopting the specifically designed interoperability initiatives previously detailed, health device profiles for Bluetooth (Health numerous studies have been developed over the Device Profile, HDP), ZigBee (Health Care, last decade. In [3] the authors propose a gateway HC), and USB (Personal Health Device Class, architecture enabling devices in a DLNA-based PHDC). In February 2011, Continua Health home network to control devices in a ZigBee Alliance signed a collaboration agreement with sensor network through DLNA. An intra-gate- Wi-Fi Alliance for the promotion and adoption way for entertainment contents in Digital Home, of Wi-Fi Direct technology, and more recently, based on UPnP to provide interoperability did the same with the NFC Forum to expand among different Digital Restrictions Manage- standards-based connectivity technology in the ment (DRMs), services and content formats is health IT industry. HL7 is a set of protocols proposed in [4]. IEEE 1451 has been used by that, with the definition of a range of message different research groups to try to solve particu- types, covers the communication of a wide vari- lar problems in specific areas, as in [5], a project ety of clinical information between entities that studies integration between IEEE 1451 and

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HL7 to exchange incompatible healthcare infor- DPWS defines a lightweight subset (WS-Discov- mation generated from heterogeneous medical ery, WS-Eventing, WS-Transfer, WS-Security ROA is a specific set information systems. In [6], a multimedia service and WS-Policy) of profiles within the WS suite, platform to create multisensory media effects for which are oriented to embedded systems and of guidelines for heterogeneous appliances and a home server in devices with limited resources. The main disad- implementing a the ubiquitous home networks is presented. This vantages of DPWS, as discussed in [11], are the REpresentational work adopts UPnP to enhance compatibility overhead, since it uses eXtensible Markup Lan- among devices. In [7], a cross-domain applica- guage (XML) for data representation and the State Transfer (REST) tion is proposed for a non-compliant ISO/IEEE SOAP-over-HTTP binding for the communica- architecture, which 11073 PHD device, i.e., Nintendo’s Wii Balance tion part. To overcome these limitations, the plus a virtual ISO/IEEE 11073 PHD weighing proposal in [11] presents an enhanced procedure uses similar architec- scale. The majority of these projects propose that comprises the Efficient XML Interchange tures to the web. tailored technologies and protocols that make (EXI) compressor and the SOAP-over-CoAP As opposed to REST, use of specific applications and, at upper levels, binding for transport of SOAP messages in generic gateway architectures and abstraction resource constrained environments. SOA is essentially layers to overcome the interoperability gap. Most of the platform proposals for integra- designed to separate Even though these types of approaches enable tion, especially in Wireless Sensor Networks integration of non-compatible technologies [8], (WSN), implement SOA. For instance, in [12], a functions or they are only isolated applications, suitable for service-oriented architecture for delivering automation services. specific scenarios. e-Health services at home using a hardware plat- The appearance of the “Web of Things” form such as a residential gateway is proposed. paradigm, led by the emerging 6LoWPAN and In [13], a solution to connect isolated Open Ser- Internet-based technologies, proposes a new vices Gateway Initiative (OSGi) frameworks and integration level, not only for the network (the support the usage of native DPWS devices and previous “Internet of Things” vision), but also services is presented. In [14], DPWS is integrat- for the web. By using existing and ubiquitous ed as a comprehensive middleware for e-Health web protocols as common ground, the resources devices, and [15] describes a DPWS-based open of different devices can be used to create new architecture for home service development. In applications, thanks to this open interface [16], a framework to design and implement inte- approach. In this context, there are mainly two grated services for home network appliances prevailing architectural tendencies for building with SOA, although not using DPWS, is pro- distributed systems, as stated in the Introduc- posed. Finally, [17] presents a design and imple- tion: SOA and ROA. Choosing between these mentation of a SOA that integrates UPnP and two approaches implies different advantages and DPWS in an OSGi framework and using ZigBee drawbacks, as discussed in the following. and Bluetooth to merge a number of service ori- OASIS defines SOA as “a paradigm for orga- ented applications. nizing and utilizing distributed capabilities that ROA is a specific set of guidelines for imple- may be under the control of different ownership menting a REpresentational State Transfer domains. It provides a uniform means to offer, (REST) architecture, which uses similar archi- discover, interact with and use capabilities to tectures to the web. As opposed to REST, SOA produce desired effects consistent with measur- is essentially designed to separate functions or able preconditions and expectations.” SOA is automation services. A SOA architecture, con- based on a design paradigm that specifies the sisting of a number of services, merges such creation of automation logic in the form of ser- “functionalities” into one overall feature. How- vices. Therefore, an architecture oriented to ser- ever, REST standardizes the traditional func- vices facilitates the separation of problems. The tions, i.e., GET, PUT, POST and DELETE (in popularity of SOA began with the advent of case of HTTP connectors). REST is not defined Web Services (WS), which enable interoperable upon method definitions, but it requires meth- machine-to-machine interaction over a network, ods to be uniformly defined for all resources by allowing different services to be homoge- (i.e., intermediaries do not need to know the neously published, discovered and used in a resource type to understand the request). There- standard technology-neutral form. WS are the fore, the implementation of a RESTful service is most common way, albeit not the only one, for usually easier and more lightweight than in implementing SOA architectures, but it is impor- SOA. tant to underline that SOA does not imply using These features could lead designers to believe WS because they are different concepts [9]. that REST is the most interesting candidate to There are several specifications associated build a universal and interoperable interface for with WS with different degrees of maturity, sup- smart things. However, implementing RESTful ported by various SDOs. These specifications are architectures for communication between devices the basic WS framework established by first-gen- is a complicated task and still requires further eration standards: Web Services Description research efforts (some related results are pre- Language (WSDL), Simple Object Access Proto- sented in [18]). A major drawback is the way col (SOAP), and Universal Description, Discov- that ROA architectures perform asynchronous ery and Integration (UDDI). Specifications may messaging [19]. Nevertheless, a number of alter- further complement, overlap, and compete with natives to overcome this limitation are proposed each other. The Web Services Discovery and the in [20]. As mentioned above, choosing an archi- Web Services Devices Profiles (WS-DD) [10], tecture depends on the type of application to be which are based on the Devices Profile for Web developed. An existing evaluation study con- Services (DPWS), are noteworthy efforts among cludes that REST is an architectural style for the the profiles occasionally referred to as “WS-*. web, while SOA can be used to build a middle-

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ware of interoperable standards [21]. One of the provided by existing specifications and dynami- An ontology makes most important applications of applying the cally wrapped into semantic services is pro- REST architectural style is the development of posed. it possible to share physical mashups [22], which can be defined as Mashups and ontology-based solutions are common under- applications that seamlessly integrate different not mutually exclusive. For example, as pro- standing of the data sources on the web. Mashups feature some posed in [29], the automatic generation of characteristics, such as: mashups based on an ontology-based model, can structure of informa- •Accessibility — devices are modeled as be merged. tion among people resources of the web under different repre- sentations. ONCLUSION or software agents, •Findability — resources are indexed by C to enable reuse of search-engines (lightweight-metadata). This article provides a comparative overview of domain knowledge, •Sharing — data are shared through Social the main wireless communication technologies Access Controller (SAC) architectures for consumer networking that can be applied in to make domain using different web applications (such as home environments such as entertainment, assumptions explicit, Friends and Things, FAT). home automation or e-Health. Since transport •Composition — data are a combination, a technologies are not enough to exchange dis- to separate domain presentation or a functionality derived from parate information seamlessly, high-layer inter- knowledge from the two or more sources for creating a new ser- operability protocols are required. Therefore, operational knowl- vice. this work also describes a comprehensive compi- There are several examples of physical lation of the major interoperability proposals edge, and to analyze mashups in the Internet, such as: Sensorpedia and initiatives for the considered domains. Nev- domain knowledge. [23], which provides enterprises and organiza- ertheless, a higher application layer is also tions with methods to share sensor information required if cross-domain integration is to be solving the actual lack of PnP features applied to achieved. Consequently, a reasoned discussion of data sources; Pachube [24], which gives people tendencies on abstraction-based architectural the power to share, collaborate, and make use of approaches that can be used to overcome the information generated from the world around concerns that arise because of the fragmented, them; or Sensor.Network [25], which allows isolated realities of low-layer stacks are also cov- researchers and scientists to share data with ered within this manuscript. As a result, a com- authorized partners, which can manage sensor plete protocol stack overview, from available installations, visualize collected data and share it transport technologies to existing and emerging with trusted partners. architectural approaches, is also discussed by Another possibility to provide formal and putting at the disposal of the readers a useful high-level interoperabilitty is the use of ontolo- tool to select an appropriate combination of gies. An ontology defines a set of representa- technologies, standards, and architectures for tional primitives for modeling a domain of their complete stack. knowledge [26]. The main purpose of the seman- tic web and ontologies is to integrate heteroge- ACKNOWLEDGMENTS neous data and enable interoperability among This research work has been partially supported disparate systems. Ontologies are used to model by projects TIN-2011-23792 of the Innovation software engineering knowledge by denoting the and Science Ministry (MICINN) and European artifacts that are designed or produced during Regional Development Fund (ERDF), TSI- the engineering process. Essentially, an ontology 020100-2010-277 Plan Avanza I+D of the Minis- makes it possible to share common understand- terio de Industria, Turismo y Comercio ing of the structure of information among peo- (MITyC), PI029/09 of the Gobierno de Aragón. ple or software agents, to enable reuse of domain knowledge (e.g., to share the same concept in REFERENCES different domains), to make domain assumptions [1] IEEE Std Computer Dictionary. A Compilation of IEEE explicit, to separate domain knowledge from the Std Computer Glossaries, IEEE Std 610. operational knowledge, and to analyze domain doi:10.1109/IEEESTD.1991.106963, 218 pages, 1991. [2] A. Aragüés et al., “Trends and Challenges of the Emerg- knowledge. ing Technologies towards Interoperability and Stan- In this context, [27] suggests an approach in dardization in e-Health Communications,” IEEE which each node of the WSN has a repository Commun. 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[8] F. Ding et al., “Design and Implementation of ZigBee [28] S. Zhexuan, A. A. Cárdenas, and R. Masuoka, “Seman- based Gateway for Environmental Monitoring System,” tic Middleware for the Internet of Things,” Internet of IEEE Int’l. Conf. Commun. Tech. (ICCT’08), 2008, pp. Things, 2010, pp. 1–8. 93–96. [29] F. Bakalov et al., “Ontology-Based Multidimensional [9] D. Sprott and L. Wilkes, “Understanding Service-Orient- Personalization Modeling for the Automatic Generation ed Architecture,” CBDI Forum, 2004. http://msdn. of Mashups in Next-Generation Portals,” Int’l. Wksp. microsoft.com/en-us/library/aa480021.aspx. Last visit: Ontologies in Interactive Systems, 2008, pp. 75–82. 01/2012. [10] Web Services Discovery and Web Services Devices Pro- file (WS-DD), OASIS Open, http://www.oasisopen.org/ BIOGRAPHIES committees/ws-dd/. Last visit: 01/2012. [11] G. Moritz, F. Golatowski, and D. Timmermann, “A ANTONIO ARAGÜÉS ([email protected]) received the MS Lightweight SOAP over CoAP Transport Binding for degree in telecommunication engineering and M.S. degree Resource Constraint Networks,” IEEE Int’l. Conf. Mobile in biomedical engineering from the Aragón Research Engi- Ad-Hoc and Sensor Systems, 2011, pp. 861–66. neering Institute (I3A), University of Zaragoza (UZ), Spain, [12] A. Hein et al., “A Service Oriented Platform for Health 2006 and 2010, respectively, where he currently works. His Services and Ambient Assisted Living,” Int’l. Conf. research interests include e-health, mobile solutions, multi- Advanced Information Networking and Applications media services, wireless communications, biomedical appli- Wksps., 2009, pp. 531–37. cations and architectures, and interoperability and [13] O. Dohndorf et al., “Towards the Web of Things: standardization, where he has developed several research Using DPWS to Bridge Isolated OSGi Platforms,” IEEE projects within the I3A research line of telemedicine. Int’l. Conf. Pervasive Computing and Communications Wksps., 2010, pp. 720–25. IGNACIO MARTÍNEZ ([email protected]) was born in Zaragoza, [14] G. Moritz et al. “Web Services to Improve Interoper- Spain, in 1976. He received the MS, DEA, and Ph.D. ability of Home Healthcare Devices,” Int’l. Conf. Perva- degrees in telecommunication Engineering and bioengi- sive Computing Technologies for Healthcare, 2009, pp. neering Doctoral Program from the Aragón Research Engi- 1–4. neering Institute (I3A), University of Zaragoza (UZ), [15] A. Bottaro and A. Gérodolle, “Home SOA — Facing Zaragoza, Spain, in 2000, 2002, and 2006, respectively. His Protocol Heterogeneity in Pervasive Application,” Int’l. research interests include telemedicine, quality of service Conf. Pervasive Services, 2008, pp. 73–80. on multimedia services and interoperability and standard- [16] M. Nakamura et al., “Implementing Integrated Ser- ization, where he is a Coordinator of standard-based solu- vices of Networked Home Appliances Using Service Ori- tions for e-Health services with more than 30 published ented Architecture,” Int’l. Conf. Service Oriented papers. Computing, 2004, pp. 269–78. [17] R.T. Lin et al., “OSGi-Based Smart Home Architecture PILAR DEL VALLE ([email protected]) was born in Zaragoza, for Heterogeneous Network,” Int’l Conf. Sensing Tech., Spain, in 1984. She received the M.S. degree in telecom- 2008, pp. 527–32. munication engineering and M.S. degree in biomedical [18] G. Moritz et al., “Devices Profiles for Web Services and engineering from the I3A, UZ, Spain, 2009 and 2010, the REST,” IEEE Int’l. Conf. Industrial Informatics, 2010, respectively, where she currently works. Her research inter- pp. 584–91. ests include e-health, biomedical applications, interoper- [19] S. Duquennoy et al., “Consistency and Scalability in ability, standardization, e-accessibility and usability, where Event Notification for Embedded Web Applications,” she has developed several research projects within the I3A IEEE Int’l. Symp. Web Systems Evolution, 2009, pp. research line of telemedicine. 89–98. [20] D. Guinard, V. Trifa, and E. Wilde “A Resource Orient- PILAR MUÑOZ ([email protected]) received the MS degree in ed Architecture for the Web of Things,” Internet of telecommunication engineering and M.S. degree in Things, 2010, pp. 1–8. biomedical engineering from the Aragón Research Engi- [21] C. Pautasso, O. Zimmermann, and F. Leymann, “Rest- neering Institute (I3A), University of Zaragoza (UZ), Spain, ful Web Services vs. ‘Big’ Web Services: Making the 2008 and 2010, respectively, where she currently works. Right Architectural Decision,” Int’l. Conf. World Wide Her research interests include e-health, electronic health Web (WWW’08 ACM), 2008, online: record systems, clinical models, interoperability and stan- http://doi.acm.org/10.1145/1367497.1367606, Last dardization, where she has developed several research pro- visit: 01/2012], pp. 805–14. jects within the I3A research line of telemedicine. [22] D. Guinard and V. Trifa, “Towards the Web of Things: Web Mashups for Embedded Devices,” WWW’09 ACM, JAVIER ESCAYOLA ([email protected]) received the MS 2009, pp. 1–4. degree in telecommunication engineering and Master’s [23] B. L. Gorman, D. R. Resseguie, and C. Tomkins-Tinch, degree in biomedical engineering from the Aragón “Sensorpedia: Information Sharing Across Incompatible Research Engineering Institute (I3A), University of Zaragoza Sensor Systems,” Int’l. Symp. Collaborative Technolo- (UZ), Spain, 2005 and 2008, respectively, where he current- gies and Systems, 2009, pp. 448–54. ly works. His research interests include e-health, mobile [24] Pachube, http://www.pachube.com. Last visit: 01/2012. applications, multimedia services, wireless communications, [25] V. Gupta, P. Udupi, and A. Poursohi, “Early Lessons biomedical applications, and interoperability and standard- from Building Sensor Network: an Open Data Exchange ization, where he has developed several research projects for the Web of Things,” IEEE Int’l. Conf. Pervasive Com- within the I3A research line of telemedicine. puting and Communications Wksps., 2010, pp. 738–44. [26] X. H. Wang et al., “Ontology based Context Modeling JESÚS D. TRIGO ([email protected]) was born in Zaragoza, and Reasoning Using OWL,” IEEE Conf Pervasive Com- Spain, in 1981. He received the M.S. degree in telecommu- put Commun Wksps., 2004, pp. 18–22. nication engineering from the University of Zaragoza, [27] I. Corredor et al., “Knowledge-Aware and Service-ori- Zaragoza, Spain, in 2005, and Ph.D. degree in Biomedical ented Middleware for deploying pervasive services,” J. Engineering from the University of Zaragoza, in 2011. His Network and Computer Applications, research interests include e-Health applications and archi- http://dx.doi.org/10.1016/j.bbr.2011.03.031. Last visit: tectures, biomedical informatics or medical device interop- 01/2012. erability and standardization.

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