• introduction
• Mobile distributed computing is that
domain which has 2 integrated sides
(hardware
• Side which includes –wireless network,
mobile devices- and the software side
which includes –dynamic component,
middleware).
introduction
(Cont.)
• Here in this papers the authors focused
on software side ,and they discuss
some important parts of the mobile
software developing like( functional
and non-functional properties ,software
architectural model, dynamic content
integration and composition of network
resources, WSAMI as a middleware
developed for mobile distributed
c o m p u t i n g ) .
introduction
(Cont.)
• 1. MOBILE DISTRIBUTED SYSTEM:
In one hand, this term is
considering all type of mobility like
(personal, computer, and
computational). In this paper the
author focused on (the mobility of
devices).
introduction
(Cont.)
• 2.MOBILITY OF DEVICES: Contains of
• wireless infrastructure.
• and dynamic networking .
• 2.1 wireless infrastructure: Is the heterogeneity of
network and devices,
• (GSM,GPRS,UMTS)(IEEE802.11 wireless LAN)
• 2.2 Dynamic networking: The basic role of the
dynamic networks is the management
• Of handling mobility-induced failures, to handle this
problem there is a technique
• Which called (optimistic replication) which means
the content and related service is replicated on the
wireless device to allow continuing access when
disconnection has occur.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Data-oriented system .
Service-oriented system.
3.QUALITY OF SERVICE (QOS): this term is very important in management of
Wireless network, the dynamic composition must minimize resource
Consumption on mobile nodes and satisfy the user's requirements .
3.1 QOS SPECIFICATION : must satisfy the following aspects
A) Allowing description of service latency and cpu scheduling mechanism.
B) What is required not how the requirement is implemented.
C) Describing the attributes of mobile system such as (performance, reliability,
Security and transactional properties ).
4. BASE ARCHITECTURAL STYLE: the new trend of mobile distributed
systems tend to build the composition of mobile in autonomous component
system.
For this reason a need of formal specification arises in 2 important manners
A) functional prosperities.
B) non-functional prosperities.
•
•
•
•
•
•
•
•
•
•
•
•
FUNCTIONAL SPECIFICATION:
This specification is concerning on coordination protocols among mobile
components (the interaction protocols associated with component ports)
NON-FUNCTIONAL SPECIFICATION:
This specification is concerning on performance , reliability ,service latency
,response time, the probability of service availability, the availability of network
bandwidth and security of protocol on which the mobile component
relies for secure communication .
Also the non-functional specification concerning the (wireless connectors)
Which specify the interaction protocols that are implemented over the wireless
Network.
5.DYNAMIC COMPOSITION:
Integration and composition of mobile component to ensure correctness of
The mobile distributed system which conformance the functional and the nonfunctional specification.
•
•
•
•
•
•
•
•
•
•
•
•
6. MIDDLEWARE SUPPORTING:
The middleware which involve in communication between the nodes of mobile
system, here the author have developed (WSAMI) which is service-oriented
middleware for mobile computing and this middleware is divided into
A)WSAMI-SOAP
B) Naming and discovery (ND).
WSAMI has been designed for to minimize resource consumption on the
wireless devices.
7.CONCLUSION:
1)mobile distributed system is a new trend where every component in this
system can be developed separately.
2)mobility of computation (mobile code) tend to be dynamically composed
according to the networking of mobile service which supported by integration
Resource discovery protocols within the middle ware.
3)the formal specification for each part of mobile computing is very important
To present good quality of service
4)non-functional specification is more critical aspect which requires more
effort in specification.
MY OBSERVATIONS:
1)good effort but bad paper organization.
2)The title and the abstract don’t illustrate the real content of the paper.
3) I think that the title should by :
“FORMAL SPECIFICATION FOR MOBILE DISTRIBUTED COMPUTING”
4) The authors don’t mention what kind of formal languages they used in this
paper.
5)The authors mentioned the term “AURA” as a middleware project in conclusion
Not in the contribution.
6)The authors mentioned about using RPC in mobile communication which return
The set of good matching service to the user, but RPC supports only limited
Set of simple data type and also require integrated definition language (IDL) and
doesn't support passing objects which is the main mobile code content.
6)The authors mentioned about using SOAP , which is an industry standard of
XML distributed computing infrastructure. But WML is used in mobile
computing.
REFERENCES:
SOFTWARE ARCHITECTURE FOR MOBILE DISTRIBUTED COMPUTING,VALERIE,
FERDA,JINSHAN,FRACOISE,INRIA,UR,FRANCE,2004