|
|
|
| Untersuchte Arbeit: Seite: 26, Zeilen: 1-39 |
Quelle: Bishaj 2007 Seite(n): 4, 5, Zeilen: 4: l. Spalte: 40ff; 5: l. Spalte: 6ff |
|---|---|
| It has a flexible and scalable architecture, where service browsing and human interaction is possible. SLP offers filtered search for attributes and predicates, such as AND, OR, comparators, and substring matching. SLP shares the concept of leasing with Jini and UPnP. Services can be deployed in small networks without any special configuration or deployment. It works even if there is no DNS, DHCP, SLP DA, or routing. Therefore, home networks would benefit much from the automation of service discovery, because they often lack network administration. However, the architecture with DAs makes the system vulnerable to a single point of failure. SLP is an open source, vendor independent and already implemented. It has the advantage of not depending on any programming language.
2.5.4 Bluetooth SDP Bluetooth is a transmission technology, meant for short-range (10m) wireless communication between low-power devices. Bluetooth devices form a personal area network, a piconet, with a maximum of 8 members. Groups of piconets communicating with each-other form a scatternet. Every Bluetooth SDP device has to implement a SDP server that provides services. The server has a list of service records, each with a list of attributes that represent different service classes. A Bluetooth SDP client sends a request message with the list of service classes. Bluetooth is designed for Bluetooth environments, therefore, it offers limited functionality compared to other SDPs. Its functionalities are: search for services by service type; search for services by service attributes; and service browsing without a priori knowledge of the service characteristics. The Bluetooth SDP does not include functionality for accessing services. After services have been discovered with it, the selection, access, and usage can be done with mechanisms out of the scope of SDP, for example by other SDPs such as SLP and Salutation. SDP can coexist with other SDPs, but they are not a necessity. The strong point of Bluetooth in the home environment is the lack of wires, while the short range it provides is a disadvantage. Also, it has a peer-to-peer connectivity, which does not scale well, because typically the systems lack resources. Another disadvantage is the lack of event notification when services become unavailable. The Bluetooth security mechanisms offer either one-way, two-way, or no authentication. When authentication is used, the Bluetooth devices generate a secure connection with a pairing process that makes use of PIN codes entered by users. But for home environment usage, maybe security and privacy have to be addressed also in higher layers. Bluetooth has huge implementation opportunities in home environments. Apart from cell phones and PCs which have already been implemented, there are other potentials. Home automation, for example, could replace doorbells. This would eliminate unnecessary wires around the place. Other goods, such as toys or entertainment devices, could be another area of implementation. |
[Seite 4]
It has a flexible and scalable architecture, where service browsing and human interaction is possible. SLP offers filtered search for attributes and predicates, such as AND, OR, comparators, and substring matching [5]. SLP shares the concept of leasing with Jini and UPnP. Services can be deployed in small networks without any special configuration or deployment. It works even if there is no DNS, DHCP, SLP DA, or routing. Therefore, home networks would benefit much from the automation of service discovery, because they often lack network administration. However, the architecture with DAs makes the system vulnerable to a single point of failure. SLP is an open source, vendor-independent and already implemented [4]. It has the advantage of not depending on any programming language [5]. [Seite 5] 2.6 Bluetooth SDP Bluetooth is a transmission technology, meant for short-range (10m) wireless communication between low-power devices. Bluetooth devices form a personal area network, a piconet, with a maximum of 8 members. Groups of piconets communicating with each-other form a scatternet. Every Bluetooth SDP device has to implement a SDP server that provides services. The server has a list of service records, each with a list of attributes that represent different service classes. A Bluetooth SDP client sends a request message with the list of service classes. Bluetooth is designed for Bluetooth environments, therefore, it offers limited functionality compared to other SDPs. Its functionalities are: search for services by service type; search for services by service attributes; and service browsing without a priori knowledge of the service characteristics. The Bluetooth SDP does not include functionality for accessing services. After services have been discovered with it, the selection, access, and usage can be done with mechanisms out of the scope of SDP, for example by other SDPs such as SLP and Salutation. SDP can coexist with other SDPs, but they are not a necessity [4]. The strong point of Bluetooth in the home environment is the lack of wires, while the short range it provides is a disadvantage. Also, it has a peer-to-peer connectivity, which does not scale well, because typically the systems lack resoures [sic]. Another disadvantage is the lack of event notification when services become unavailable [5]. The Bluetooth security mechanisms offer either one-way, two-way, or no authentication. When authentication is used, the Bluetooth devices generate a secure connection with a pairing process that makes use of PIN codes entered by users. But for home environment usage, maybe security and privacy have to be addressed also in higher layers. Bluetooth has huge implementation opportunities in home environments. Apart from cell phones and PCs which have already been implemented, there are other potentials. Home automation, for example, could replace doorbells. This would eliminate unnecessary wires around the place. Other goods, such as toys or entertainment devices, could be another area of implementation. [4] Christian Bettstetter and Christoph Renner. A Comparison of Service Discovery Protocols and Implementation of the Service Location Protocol. Proc. EUNICE Open European Summer School. September 2000. [5] Choonhwa Lee and Sumi Helal. Protocols for Service Discovery in Dynamic and Mobile Networks. International Journal of Computer Research, 2002. |
Ein Verweis auf die Quelle findet sich am Anfang des Kapitels auf Seite 23. Eine wörtliche Übernahme des gesamten Kapitels wird durch diesen aber in keiner Weise gekennzeichnet. Auf dieser Seite findet sich überhaupt kein Hinweis auf eine Übernahme mehr. |
|