Các thuật toán định tuyến Chuỗi đã được thực hiện trong kế hoạch bàn giao. Chuỗi thuật toán định tuyến được thêm vào chương trình bàn giao (chain-break) ở bước 5 như sau: 1. Các máy chủ lưu trữ di động sẽ gửi một yêu cầu bàn giaocác thuật toán chuỗi định tuyến sẽ được sử dụng. Trong trường hợp này, chúng ta có ba lựa chọn tuyến đường | 202 SIGNALING TRAFFIC IN WIRELESS ATM NETWORKS the sent-back bit detects that it has arrived at the ATM switch in which the chain started it will begin applying the Chain Routing Algorithm. Suppose the mobile roams into Cell 6 and one bit is sent back through the chain route. When the sent-back bit sees the CASL the Chain Routing Algorithm will be used. In this case we have three route options 1. Cell 6 - Cell 5 - Cell 4 - Cell 3 - Link C - ATM switch. 2. Cell 6 - Cell 5 - Cell 4 - Cell 3 - Cell 2 - Link B - ATM switch 3. Cell 6 - Cell 5 - Cell 4 - Cell 3 - Cell 2 - Cell 1 - Link A - ATM switch. If the BS of Cell 2 has a high ORP for example a new route 1 will be set up. IMPLEMENTATION OF THE HANDOFF SCHEME The Chain Routing Algorithm has to be implemented in the handoff scheme. The Chain Routing Algorithm is added to the handoff scheme chaining followed by make-break in Step 5 as follows 1. The mobile host sends a handoff request message to the new BS identifying the old BS and its connection server. 2. The new BS adds local translation table entries for its internal routing. 3. The new BS asks the old BS to forward packets pertaining to the mobile host. 4. The new BS sends back a handoff response message to the mobile host instructing the mobile host to transmit receive through the new station. 5. We include the Chain Routing Algorithm. A single bit is transferred from the mobile host back to the starting point of the chain route. It checks the ORP of each BS. After the new route is found and the new BS chosen which is connected to the ATM switch the new BS sends a message to the ATM switch channel server performing make break and break-make . The new BS can change its translation table entries in its BS channel server immediately and the new connection between the chain to the ATM switch is established. This way the chaining portion of the handoff is completed. Note that these five steps 1 2 3 4 and 5 are accomplished in real time. 6. The new BS passes the
