Chapter 6: Conclusion

Transcription

1 Chapter 6: Conclusion In this research we have designed the bandwidth optimization control protocol to manage the proposed Dual-bandwidth data path for the CDMA2000-WLAN integrated network. The user s request sent from CDMA2000 network and the reply got from WLAN network under the integrated network. During the data transmission, both two networks have been utilized efficiently. The designed BOCP has been simulated in ns2 Java version simulator and the simulation results have been evaluated. We have compared the simulation results with the both of the CDMA2000 and WLAN network. The higher data rates have been achieved through the Dual-bandwidth data path. This conclusion consists of for sections. We will summarize our main ideas in the section 6.1 and our main contributions will be presented in section 6.2. Following the summary and contributions, we present the research s deficiencies in section 6.3 and the future works in section Summary of main ideas The Dual-bandwidth data path and the bandwidth optimization control protocol are together efficiently utilizing the two networks bandwidth of CDMA2000 and WLAN. We have discussed our implementations into three steps: the system design, simulation and the simulation results evaluation. The purpose of the Dual-bandwidth data path design is to get higher data rates and to utilize the two network resources efficiently in the overlapping areas of CDMA2000 and WLAN networks. The proposed Dual-bandwidth data path consists of four components which are bandwidth management, bandwidth selection, packet 6-1

2 receiver and bandwidth monitor. The relationships of the four components are as follows: The bandwidth management installs and deletes the bandwidth monitor. The bandwidth monitor calculates the available bandwidth for application. The bandwidth selection chooses one appropriate path according to the bandwidth monitor report for the application. Finally, the packet receiver accepts incoming packets and then filter and reorders them before sending them into decoder. In order to design the Dual-bandwidth data path, we have established a model as presented in Figure 3-3. Our model is based on the integration architecture of CDMA2000-WLAN networks by CDG (CDMA Development Group). In the CDG integration architecture, each network provides services to mobile nodes separately. Because of the disparity in bandwidth, in which the WLAN network bandwidth is much wider than CDMA2000 network, the mobile nodes are totally handoff to access Internet through WLAN network. At this particular area, it may cause WLAN network too busy and CDMA2000 network resources wasted. In addition, the Lucent research shows that the Internet characteristics in bandwidth utilization that relates to request amounts to one fourth of the reply. For these reasons, we proposed to integrate the two network bandwidth to provide service for the mobile nodes. The Dual-bandwidth data path model that we proposed (as shown in Figure 3-3) shows that the mobile node sends request through the connection MN-BS-PDSN-CN which represent CDMA2000 network. The reply however comes from the connection CN-PDSN-AP-MN which represents WLAN network. Thus, the two networks provide services to the mobile node simultaneously. Our proposed solution is a novel solution, which unlike any other solutions that mainly focused on total handoff. 6-2

3 In order to establish the Dual-bandwidth data path, we have proposed the bandwidth optimization control protocol (BOCP). The Dual-bandwidth data path utilizes the two networks bandwidth in the integrated architecture of CDMA2000- WLAN. Data requests will be controlled by PCF (Packets Control Function) in CDMA2000 network and data reply will be controlled by PDIF in WLAN network. Data traffic is routed through PDSN from CDMA2000 network to WLAN network. Mobile node is assumed featured with a wireless interface that works on the two different access technologies. The BOCP design is based on the WLAN protocol and frame structure. In the Control Frame Field of the WLAN frame structure (as shown in Figure 2-6), there are three items related with our research as follows: Type/Subtype field: Type/Subtype field indicates frame type; Duration/ID field: Immediately following the Frame Control field in the IEEE MAC header is the Duration/ID field. The Duration/ID field carries the association identity (AID) of the station that transmitted the frame; and Frame Check Sequence (FCS): FCS computes over the entire aggregate header. Based on the WLAN frame structure, we proposed the BOCP frame structure as follows: Command field: The command field defined message type and subtype of request or response; Routing Domain field: The routing domain field is used to indicate that mobile nodes of one routing process can be located in both WLAN and CDMA2000 domains; and Next Nod field: The NextNod field is set to IP address of the next node along the established connection. 6-3

4 After proposing the BOCP, the simulation-based experiments employed to evaluate the BOCP enhancement. In order to implement the BOCP, six main classes have been created. They are BOC class, BOCA class, BOCPMessage class, MobileNode Class, Route Class and RoutingTable class. The relationship of the six classes is: The BOC class is responsible for generating BOCP messages and sending them to the correct destinations. The BOCA class holds network information about the interfaces associated with a particular node of the correct destination so that the BOCP messages can be sent to. The BOCPMessage holds the necessary information to update the particular node s routing table. The MobileNode class contains the particular node and the interfaces associated with that node. The Route class holds information about which interface to send packets out for a particular destination together with the IP addresses of its neighbors. The RoutingTable class is used to store all of the route objects. To implement the BOCP simulation, it is essential to understand the functionality of the BOCP and its requirements. The functionality of the BOCP in the simulation is to be able to send the BOCPMessage which is generated by the BOC class. The BOCPMessage is used to update the RoutingTable class. The simulation implementation requirements have shown the need for five main classes. The first and the most important class would be the class responsible for generating updates, sending them out, receiving updates and updating routing tables. This class is called the BOC class. Another important class is the class which holds all the information about the links in the network, i.e. the BOCA class. The other three classes are the classes to represent routes, routing tables and the update messages that get sent out. These are respectively implemented in the Route, RoutingTable and BOCPMessage classes. 6-4

5 The relationships between the Simulator class and the main five classes have been illustrated in Figure The implementation classes and their functionalities have been illustrated in Table 4-2 as well. In order to implement the simulation, we have established a simple network of four nodes. The application requests send out through the MN to the BS and the PCF, finally arrive in the PDSN and the CN. The replies come through the CN and the PDSN to the PDIF and the AP, finally arrive in the MN. The first route is the replacement of the CDMA2000 network and the second route is the replacement of WLAN network. After implementation, we have captured the related data in an output file. The output file shows that the Dual-bandwidth data path has been established. In order to verify the generated data validity and reliability, the necessary tests have been done as follows: To verify that the routing table is updated with the appropriate routes entry; The BOCP packet test for routing table information; and The BOCP test for updating the routing table. The simulation results and discussion have been illustrated in chapter 5. Figure 5-1 and 5-2 are the CDMA2000 and WLAN network model, respectively. Figure 5-3 is the proposed simulation model. Figure 5-4 and Figure 5-5 are the simulation implementations. Following the simulation implementation results, we compared the throughput, packet delay time and buffer requirement with the standard of CDMA2000 network and WLAN network. Throughput is used to evaluate the performance of the bandwidth utilization and buffer requirement is used to evaluate the performance of the Dual-bandwidth data path. The comparisons of the application services provided through the proposed Dualbandwidth data path and both two CDMA2000 and WLAN networks have been 6-5

6 illustrated in Figure 5-6, Figure 5-7 and Figure 5-8. From the illustration, the application got much higher throughput through the Dual-bandwidth data path. The comparisons of the packet delay time have been illustrated in Figure 5-9 and Figure The proposed BOCP and the Dual-bandwidth data path have reselected the wider bandwidth and achieved the shorter packet delay time. In the Figure 5-11, we have illustrated buffer requirement of the proposed BOCP with the Dualbandwidth data path. From the illustration, the buffer requirement is much fewer than the CDMA2000 network. 6.2 Contributions of this thesis In this research, the Dual-bandwidth data path has been designed and the BOCP protocol has been developed to support mobile nodes through WLAN and CDMA2000 wireless data networks within 4G wireless systems. The overall output results of the work presented in this thesis are listed below and are considered to represent the contribution of this work to the field of the Dual-bandwidth data path for 4G wireless mobile wireless Internet. The development of a Dual-bandwidth data path based on the bandwidth disparity of WLAN and CDMA2000 networks. The bandwidth of WLAN network is much wider than CDMA2000 network. In addition to its application in the two networks, the uplink load is much lighter than the downlink load. The development of the Bandwidth Optimization Control Protocol (BOCP) which is related with the Dual-bandwidth data path that we proposed; Higher Data Rates. The majority functionary of the bandwidth optimization control protocol is to distribute data into Dual-bandwidth data path for 6-6

7 transmission, which CDMA2000 data path is used for uplink traffic services and WLAN data path is used for downlink traffic service in order to utilize network resources efficiently and increase data rates; A network level simulation tool. The system design and implementation is based on ns2 Java version (Java Network Simulator), in which a network level simulation tool has been proposed, which can be used to support future research. 6.3 Deficiencies Although the work undertaken in this thesis has addressed and tried to solve certain shortcoming of the bandwidth utilization efficiency for 4G wireless mobile Internet networks, especially in the integration of CDMA2000-WLAN networks. Deficiencies were also reported during the evaluation experiments. These deficiencies are: Deficiencies of BOCP Protocol Simulation In this work, a simple network of four nodes has been established and several tests have been done to experiment the BOCP protocol on the Dual-bandwidth data path between the integration of CDMA2000 and WLAN networks. These experiments have been shown that the Dual-bandwidth data path has been established and the BOCP message has been transmitted on it properly. The performance has been evaluated through comparison of the Dual-bandwidth data path with CDMA2000 network data path. From the comparison, we can see that the Dual-bandwidth is much wider than the CDMA2000 bandwidth and the Dual-bandwidth data path can provide higher data rates. Mean whiling, the two network resources have been utilized efficiently since data requests send through CDMA2000 network and the reply is from WLAN network. 6-7

8 Form Lucent research, the most of Internet application request is amount one fourth of the reply. The Dual-bandwidth data path design fulfills the Internet application requirements. For these reasons, we thought that the BOCP protocol simulation and the performance evaluation should concentrates on comparison of the Dual-bandwidth data path with CDMA2000 network and WLAN network. The results of the comparison show that we get expected demands. But the work in this thesis hasn t been considered the special case i.e. the Internet application request is same as the reply. It will be advantage if we took the special case in the research Deficiencies of Dual-bandwidth Data Path Design The Dual-bandwidth data path design consists of four components which are bandwidth management, bandwidth monitor, bandwidth selection and packet receiver. The bandwidth monitor is keeping monitoring and calculating of the available bandwidth on the two networks. This would be taken time for the system. In addition, the bandwidth selection needs to reselect WLAN bandwidth data path after getting the indicator from the bandwidth monitor. This would be taken time for the system as well. Since the work in this thesis only concentrates on establishment of the Dualbandwidth data path within the CDMA2000 and WLAN networks, we have considered and compared the packet queuing time delay with both CDMA2000 and WLAN networks, but we ignored the packet reselecting bandwidth time delay. It will be great advantage if the time delay is considered and the performance is evaluated Deficiencies of Match the BOCP with TCP/IP TCP/IP suite is a protocol standard that comprises the two layers present in almost every Internet message. TCP is the Transport Control Protocol. It is the connectionbased protocol that verifies that message is received at destination. TCP will 6-8

9 retransmit messages that aren t correctly received and report an error if the message can t be delivered or if the connection is lost. IP is the Internet Protocol. The Internet Protocol routes messages, fragments large messages into multiple packets along with a number of other important tasks. Together, these protocols reliably move data from a sending station to a receiving station. The BOCP protocol must work with the TCP/IP protocol to provide data services to mobile users through Internet. During the BOCP simulation, some conflicts occur with the TCP/IP protocol. It will be great advantage if these conflicts can be solved in the work. 6.4 Future Works As mentioned in the introduction, the existing bandwidth resources management techniques [89] can be classified into two categories i.e. network layer resources management techniques and transport layer resources management techniques. The major objective of the network layer techniques is to reduce the rerouting packet loss, and transport layer techniques are mainly proposed for the reliable data transmission. When the mobile node moves into WLAN overlapping region from CDMA2000 coverage area, the bandwidth resources management is governed by PDSN. This process is transparent to mobile IP, and this mobility is supported by mobile IP. In this case, the fields of Dual-bandwidth data path involve many advances in technologies. These include data transmission, bandwidth utilization and the coverage of wireless networks. Improvements in any of these areas will further lead to the improvement of these fields. The work has been undertaken has been limited to development of a protocol simulation model and is not intended to be compared to a realistic behavior of devices at this time. Furthermore, the performance of the Dual- 6-9

10 bandwidth data path has been limited to other networks such as WCDMA and TD- SCDMA. Throughout the development of this work, there are certain problems that have been faced and identified. Some of the problems have been solved but some, because of the time limitation, will be proposed for future work to further enhance the system. This section intends to propose some improvements that can be undertaken in the future work The Dual-bandwidth Data Path Further Enhancements Future wireless mobile Internet [90] is going to support service provider portability, and the mobile node must be able to communicate in more than one system or networks, such as WLAN, WiMax, Bluetooth, WCDMA, TD-SCDMA and CDMA2000. The Dual-bandwidth data path design is based on CDMA2000 and WLAN networks. The work in this thesis, however, has provided a foundation for future enhancement and provides the basis where this thesis can be improved further. Future improvements, which can be added and improved features are: The Dual-bandwidth data path between WCDMA and WLAN. Since 3GPP has issued the integration of WCDMA and WLAN, the bandwidth integration between the WCDMA and WLAN is possible as well. In addition, the integration of TD-SCDMA and WLAN has not been issued by any research group. Therefore, the Dual-bandwidth data path between TD-SCDMA and WLAN is impossible for the time being now. The Dual-bandwidth data path between WiMax and WCDMA, CDMA2000 and TD-SCDMA. The research group of CDMA Development Group (CDG), 3GPP and 3GPP2, has not issued the integration architecture of these cellular networks with WiMax. Once the integration architecture proposed, the 6-10

11 integration of the bandwidth between the WiMax with these cellular networks can be further proposed. The Dual-bandwidth data path between Bluetooth and WCDMA, CDMA2000 and TD-SCDMA. From the time being, nobody can give a solution about the integration. If any possible in the feature, we will consider adding the feature into our system The BOCP protocol Further Enhancements The BOCP protocol is designed for the Dual-bandwidth data path between CDMA2000 and WLAN. In other words, the BOCP protocol works on the CDMA2000 and WLAN protocol. Therefore, it can not work on the WCDMA, TD- SCDMA and WiMax protocols. Once the Dual-bandwidth data path further enhanced, the necessary protocols are needed to be developed. These protocol including: The protocol for the integration of WCDMA and WLAN networks or TD- SCDMA and WLAN networks. In other words, the new protocol will be run on the WCDMA, TD-SCDMA and WLAN protocols. Once the CDMA2000, WCDMA and TD-SCDMA integrate into MC-CDMA, the new protocol should work on the MC-CDMA and WLAN protocols. The protocol for the integration of CDMA2000, WCDMA and TD-SCDMA with WiMax. If those research groups can integrate these cellular networks into MC-CDMA, the new protocol will be designed for the MC-CDMA and WiMax only. In other words, the new protocol works on the MC-CDMA and WiMax protocols. For the Bluetooth, no any research involved with the integration of Bluetooth and these cellular networks until time being now. Thus, it is no need to 6-11

12 develop the protocol for them. If the integration can be issued by any research, the new protocol for the integration will be proposed. 6-12