Introduction Infrastructure for pervasive computing has many challenges: 1)pervasive computing is a large aspect which includes hardware side (mobile phones,portable computers, PDA`s, embedded computing devices….etc) and software side. 2)integrating all devices with applications to provide needs of the customer which is the main domain in future. 3)providing highly dynamic environments (resources, network connectivity, software service) over any type of device, over any kind of software and for any customer seeking a service.

Vision : 1) computing landscape in future will provide an environment which support the computers to be autonomous devices that provide largely services and tasks for users. 2)application must be more intelligent to reduce the wariness of customer to direct interact with applications Assumption : The authors have some ideas for the future of pervasive computing And present some challenges in this field. These ideas and challenges will be as following: they assume a conceptual model for pervasive computing infra structure which will be as following: high level model which consists: a. devices b. users c. software components. d. user interface.

thus, this model has 4 components,authors represent every component and its challenges. 1. devices: challenges: a) device heterogeneity: PDA, mobile phones, laptop, sensors, etc… B) device mobility: maintenance of connections when the device moves between areas of different networks, handling networks disconnections. 2. software components: challenges : a) mobility and distribution: the transparency of software over several devices at the same time b) context awareness: must facilitates gathering of information from resources such as sensors, monitors, must perform interpreting of data, integration of data from different resources. C) adaptation :must resolve complex problem of managing software component that used simultaneously by applications with different requirements.

D) interoperability: using different programming language. E) component discovery: the problem management of discovery the resources Repositories. F) development and deployment. G) scalability: of devices and software (infrastructure, interaction between component, software service proving) 3. users: A) user context: infrastructure must maintain context data related to users B) user mobility: user mobility between devices must be supported by enabling automated migration. 4. user interface: A) universal interface B) adaptation C) usability: user friendly to keep attention, must be enjoyable, must provide the common interaction that can be used over different soft wares, must be designed for ordinary people

Authors opinions about existing technology: 1)context models: existing sentient (sensor) computing concerning in supplying context information to application, focusing on information location, using CORBA to facilitate the communications. 2)service platform: existing platforms focus on rapid creation and deployment of service, JINI and RMI. 3)appliance environment: to support interoperability among collection of appliances (tools). 4)pervasive computing environments: anytime, any where 4.1 PIMA : decouple application logic from details 4.2AURA : proposes a programming model for task based computing. 4.3 PORTOLANO: focus on infrastructure rather than software development. Research Agenda: 1)dynamically discovering software components in changing enlivenments 2)increasing of autonomous applications 3)increseaing of developing flexible software components. 4)ability of integrate heterogeneous computing enlivenments. 5)increasing new novel type of user interface.

Technical review: 1) using some abbreviations without mention to the original of the words (JINI, RMI, CORBA, DCOM,LDAP, PDA,URL,MOCA,,HAVI,PIMA,AURA, PORTOLANO) 2)The assumed model concentrates on some aspect, but there are very important Aspect which can be added like: 1).netorks protocols 2)new network topologies 3)integration the standard of networks 4)mangement of service 5)real time distributed system problem 6)carbage collection over distributed networks 3)I think that this model must be enhanced. 4)authors addressed the challenges but not the solutions. 5)their model concentrates on user interface as a n important aspect. 6)I think that if there is a unique model for every part of pervasive computing than we can integrate each one with the other For example ( model for communication issues –networks,protocols, standard etc., model for software issues, model for devices and other for user) Like the following:

pervasive computing model Model of communications model of software Model of user Model of device

References: Infrastructure for pervasive computing: challenges, Karen henricksen, Jadwiga and Andry,SCHOOL OF COMPUTER SCIENCE AND ELECTRICAL ENGINEERING, THE UNIVERSITY OF QUEENSLAND,DISTRIBUTED SYSTEMS TECHNOLOGY CENTER.,