假期工作总结.ppt

1、Mathematic Model on OPEX in Repair Process and Some Protection Architectures in Access Network,张志成 2011.11.09,Outlines,Background Mathematic Model on OPEX in Repair Process Some Protection Architectures in Access Network Some ideas on protection,Background,Background on modeling OPEN in repair proce

2、ss OPEX haven been shown a very important factor of the total cost of ownership of a telecommunication operator. In some cases, OPEX can be up to 85% of the TCO. Failure reparation is one of the most costly OPEX processes. Mathematic modeling OPEX in repair process can provide theoretical reference

3、in network designing. Providing mathematic reference on differentiated protection in distributed fibers. Background on protection in access network As the propose of NG-PON2, 40G100G PON have been proposed which make it more important to make effective and economical protection scheme in access netw

4、ork.,Mathematic Model on OPEX in Repair Process,General assumption The components (OLT,Splitter,ONU) have availability equal to one. All fiber links fail independently. The repair time and the time to fail of a fiber link are exponentially distributed random processes with constant means MTTR( Mean

5、Time To Repair) and MTTF (Mean Time To Failure). At most i fiber links can simultaneously fail in the network,Mathematic Model on OPEX in Repair Process,How to set i ? A simple model: assume a CO consists of100 PON, each PON consists of 200 users. The average length of distributed fiber is 2 km. MTT

6、R of fiber failure is 24 hours. In a year, the average failure time in one kilometer fiber is 0.005. Thus to the CO, in a year, all the distributed fibers assume to failure 200 times. One year is divided into 365*24 time slots.,Mathematic Model on OPEX in Repair Process,The continuous time Markov ch

7、ain i = 2 N is the number of users The failure rate for each distributed fiber i is , where The repair rate for each distributed fiber i is , where The continuous time Markov chain is depicted in Figure 3. If the network is in state (0), no distributed fibers fail. If the network is in state (i), on

8、ly distributed fibers i is failure. If the network is in state (i,j), both distributed fiber i and j are failure and fiber i failed before fiber j.,Mathematic Model on OPEX in Repair Process,Let be the sum of the failure rates of all distributed fibers. The state probabilities (p) are interrelated b

9、y the balance equations: We can solving Equations above for the state probabilities (p). Then based on the state probabilities, the mean failure time of each distributed fiber can be calculated.(To be solved),Protection Architectures in Access Network,Proposed Architectures Fibers protection Georgia

10、 Institute of Technology, wavelength switching of integrated tunable optical transmitter for high throughput WDM-PON. Self-Protection Scheme for WDM-PON using a Circulator-AWG Based Wavelength Router Protection scheme for WDM PON based on sub-ring architecture OLT protection 1:N OLT Redundant Protec

11、tion Architecture No cold standby equipment protection,Fiber Protection,wavelength switching of integrated tunable optical transmitter for high throughput WDM-PON ITLA: Integrated tunable laser assembly Low cost, simple architecture, centrally managed,Fiber Protection,Self-Protection Scheme for WDM-

12、PON using a Circulator-AWG Based Wavelength Route,Fiber Protection,Protection scheme for WDM PON based on sub-ring architecture Wavelengths of upstream and downstream signals of the two WDM-PONs use different four wavelength bands. The wavelength bands are separated by the free spectral range (FSR)

13、of AWG in RN. Initial connection state of the OS in ONU is port 2-3 connection. When a failure occurs, the MC in the ONU changes the OS to 1-3 connection.,OLT Protection,1:N OLT Redundant Protection Architecture: N working OLTs, one standby OLT and an 1:N optical switch for changing optical paths. F

14、ailure detection at a working OLT Failure notification Signaling to the optical switch Updating the standby OLT ONU discovery and configuration,OLT Protection,No cold standby equipment protection Protection is provided by rescheduling time slots. Half of available time slots of ONUs served by working OLT are distributed to ONUs served by failed OLT. As soon as a loss of signal is detected, protection control unit will determine the faulty OLT and