A Model Based on Multi-agent for Dynamic Bandwidth Allocation in Networks Guang LU, Jian-Wen QI

Transcription

1 216 Jont Internatonal Conference on Artfcal Intellgence and Computer Engneerng (AICE 216) and Internatonal Conference on etwork and Communcaton Securty (CS 216) ISB: A Model Based on Mult-agent for Dynamc Bandwdth Allocaton n etworks Guang LU, Jan-Wen QI Army Offcer Academy, Hefe, Anhu provnce, Chna, 2331 luguang215hf@163.com Keywords: Dynamc Bandwdth Allocaton, Agent Model, IPACT, Bargan, USR. Abstract. For the problem that tradtonal IPACT may cause superor USR, ths paper constructs the Agent dynamc bandwdth allocaton model. Introduced the dea of barganng game. Proposed a local bandwdth allocaton algorthm based on the bargan bargan. Resequencng the date packets after barganng accordng to the user level, delay and the sze of packet. It Improves the thnkng n tradtonal IPACT that date packet n order pollng. The method may effectvely solve the bandwdth allocaton problem under the acton of many factors. Experments show that the model can effectvely reduce the USR. It can also mprove the effcency of bandwdth allocaton. Introducton In tradtonal bandwdth allocaton process, OLT (Optcal Lne Termnaton) sends the data obtaned from the network to each OU (Optcal etwork Unt) after demodulatng, OU sends the receved nformaton to each user after demodulatng [1]. In ths mechansm, the data transmsson s lnear and sequental [2], f the mult-factors were actng on dfferent applcatons, ths mechansm can t effectvely solve the problem of queue schedulng. If t has nteractons between dfferent busness and the busness user level, delay, packet sze and other factors ntertwned, the neffcency of allocaton wll be reduced [3].And for the tradtonal bandwdth allocaton process, the algorthm whch OLT and OU used n bandwdth allocaton s the nterleaved pollng wth adaptve cycle tme (IPACT).In ths algorthm, t takes bytes as the unt to calculate, but n the schedulng of the queue, t us packet as a unt. Thereby, t caused the phenomenon that the bandwdth wll be set asde f the bandwdth less than a packet length, and also, t wll have a greater USR (unused slot remander) and result a waste of bandwdth resources[4]. To solve these problems, we use the methods of Agent-based modelng for busness modelng n OLT and OU, abstractng the related factors n bandwdth allocaton, t may mprove the model's ablty to descrbe the complex factors. For the desgn of the algorthm, we ntroduced the dea of gamng based on IPACT and desgned a redstrbuton algorthm of local bandwdth based on bargan bargan. Accordng to the perspectve n economcs, we beneftted the bandwdth allocatons and establshed three barganng condtons of user grade, packet sze and delay, t may resequencng the busness after fully barganng, and also, t may solve the queung problem of date packet n transmsson process better. Accordng to the experment, ths method can elmnatng the transmsson slots and enhance the effect of the elmnate about USR. Agent Model Lmtatons of the Tradtonal Bandwdth Allocaton Models In the pont of economcs, the benefts of the acquston s proportonal to the resources offered, and also, n the process of bandwdth allocaton, f the resources of the bandwdth s assured, the fewer users n the network, the less congestons wll be encountered n the transmsson process. Therefore, the effcency of the network wll get hgher, the qualty of the web servce wll get hgher, and the prce of the bandwdth wll relatvely cheaper [5].Accordng to the analyss, there are also related factors on the process of network dspatch, such as user level, delay, packet sze etc. In addton, wth the real-tme changes n the envronment of network, the request of the bandwdth

2 allocaton wll also changed n real-tme, these factors wll affect the effcency of bandwdth allocaton, but the current bandwdth allocaton modelng used mostly use the holstc way of thnkng, t has no stratfed decomposton for the demand, t can t descrbe the nfluence of the bandwdth allocaton whle multple factors exst, t may cause the lower effcency of allocaton, the greater latency and other ssues. The methods of Agent-based modelng s an effectve way for the analyss of complex systems. Ths method s a top-down analyss and bottom-up ntegrated way for complex system, t can effectvely sort out the system and abstract relevant factors easly whch affectng network bandwdth allocaton. Ths model may mprove the descrpton ablty of multple nfluencng factors [6]. Model Establsh Accordng to the dfferent types of busness n networks, we modeled OLT and OU by sub-agent. For each OLT and OU, we classfed the date packets by busness and establshed the busness Agent as a basc unt of the model to descrbe the network bandwdth usage. In real networks, for a separated busness, there wll be dfferent SLA(servce level agreement) accordng to the dfferent needs of ts transmsson. Use SLA to descrbe dfferent busness may be able to express the effect of user level, arrval tme on bandwdth and tme delay clearly. Thus, we abstracted all the dfferent SLA classes n each busness and establshed SLA Agent. In network envronments, there are a lot of applcatons connected to the OLT and there wll be a number of applcatons for each user of the SLA class. These applcatons may be the same or may be dfferent, and n the same way, for the same applcaton, t may also exst n several SLA class. Abstract the applcatons of each SLA may descrbe the nteracton clearly between the varous applcaton classes n bandwdth allocaton process. Thus, we establshed the applcaton Agent. There wll also have some dfferent users under each type of applcatons, and when the users are nvolved n the process of the network, they may have dfferent bandwdth requrements, latency requrements and prorty needs, these factors may affect the effcency of bandwdth allocaton drectly. Thus, regardng the user as an abstract factor for each type of applcaton decomposton may helps to break down the bandwdth requrements more deeply. Based on ths, we establshed the user Agent. For dfferent users, prortes, arrval tme and packet length wll affect the user s bandwdth acquston whle partcpatng n the network. These factors together consttute the user s level that s the order of the date packets n the bandwdth allocaton process. Accordngly, takng user level as an abstracton to buld user level Agent may make t easly to descrbe each user n networks. Based on the analyss above, we establshed the bandwdth allocaton model; t s shown n Fgure 1. Fgure 1. A Dynamc Bandwdth Allocaton Model Based on Agent.

3 In ths model, we recorded the user level UL,packet arrve tme AT, length of packet PL,and set coeffcent above the three factors whch represent the mportance of the nfluence n bandwdth allocaton, ts value changes wth dynamc bandwdth allocaton requrements. The user level s dvded nto 1 to 1, s the weght of the user, and t s value ncreases exponentally wth the ncrease of user level. The relatonshp between and user level s shown n fgure 2. weght user level Fgure 2. The Relatonshp between User Level and Weght. weght Thresthod-(TmeCurrent-AT) Fgure 3. The Relatonshp between Tthresthod Tmecurrent AT and. s the weght of packet arrval tme AT. If the current tme meet wth the followng condtons, the date package was effectve, otherwse, the packet was lost. T Tme AT thresthod current (1) In the above formula, T s the threshold of delay. When the thresthod Tme current AT s closer to T, thresthod the value of wll get greater. The relatonshp s shown n fgure 3. s the weght of the date packet length PL. If the longer the packet length,the longer the arrve tme,the weght of PL wll get greater. The relatonshp between PL and s shown n fgure weght data packet length Fgure 4. The Relatonshp between Packet Length and. Up UL AT+ PL 1 (2)

4 Accordng to the analyss of the three parameters of the user level UL, the packet arrval tme AT and the packet length PL,we can get the comprehensve effect evaluaton parameters U p of the busness p among the th busness: Up UL AT+ PL 1 IPACT (Interleaved Pollng wth Adaptve Cycle Tme) Process of the Model The core dea of the tradtonal IPACT algorthm s Request-Grant- Report, that s the OLT send the Grant nformaton to the approprate OU accordng to the nformaton n pollng lst. After the OU be authorzed, t send the data through the passve optcal spltter whle t s wndow opened, and add a report nformaton at the end of the data to tell the OLT the remanng sze of bandwdth and other nformatons n the cache about the OU, t may be prepared for the next authorzaton[7]. As mentoned above, ths algorthm wll have a greater USR and resultng n a waste of bandwdth resources. Based on the tradtonal IPACT algorthm and combned wth the Agent model establshed, we use the OU Agent and OLT Agent as the basc unt to pollng and proposed an mproved IPACT algorthm shown n fgure 5: (3) Fgure 5. The Process of IPACT. The specfc process of the algorthm s as follows: 1) Do the bargan between the OU Agent, the OLT Agent of the Busness class use the OU Agent whch selected by the gamng Send bandwdth request; 2) OU Agent calculates the amount of the bandwdth requrements and reports t to the OLT; 3) Authorzng the OLT Agent based on the DBA algorthm and calculatng USR, after that, the OLT Agent recordng the USR to the next query; 4) The OU reportng the authorzaton to the OLT and packng the USR to the next OLT accordng to the mechansm of the queue management. Compared to the tradtonal IPACT process, ths mechansm ntroduced a barganng game theory. In ths mechansm, the data of the network are classfed accordng to the barganng game after fully selecton, and t may select the OU whch the sze of bandwdth are adapted to the requrements to send the query request,t may mprove the accuracy of query, ths mechansm can enhance the effcent of elmnaton about USR. The Desgn and Smulaton of the Algorthm The Dynamc Bandwdth Allocaton Prncples Based on Gammng Accordng to the model constructed n ths paper, we use the prncple based on barganng to sort the onlne users whle sort the queue of each knd of busness, t can solve the schedulng problem preferably whle mult nfluence factors appled to dfferent applcatons.

5 Accordng to the model we establshed and the mproved IPACT process, the man nfluencng factors for barganng s delay, user ratngs and the sze of packet. Accordng to the theory of barganng game, we establshed the standards of barganng by the consttuton of the three factors mentoned above. In a pollng cycle, for the busness p whch has m knds of SLA, we use SLA lm pto represent the nfluencng factors of gammng, regardul p as the user class, regard PL p as the sze of packet, regardul p as the latency. In the equaton, T means the arrve now tme of users andt threshold means the threshold of the delay n ths cycle. Thus, we can choose the optmal object functon of the OU Agent. S arg max U p U mn 1 (4) U In ths functon, p may calculated by the functon (4), mn s the mnmum values of the comprehensve assessment from the expermental tests. We may gve a new functon(5) after do the logarthmc treatment of(4): U S arg max 1 ln U p U mn (5) For each busness class arrves, we establshed the rules of the gammng based on the three factors mentoned above. In a cycle, we may ascertan the order of pollng after sort the class of each busness under the prncple establshed. The Mechansm of the Elmnaton of USR Some paper proposed a method of the elmnaton of USR called baton[8].it pont out that n a cycle, whle the 2 adjacent OU satsfed wth the condton: t g r 1 m t t RTT / 2 RTT / 2 (6) Fgure 6. The Elmnaton Mechansm of USR. The relay may be succeed, and the USR of the prevous OU may be elmnated. The dsadvantage of ths method s that the probablty of the success of relay s low. After re-sequencng, the queue wll have USR whle pollng because the dfferences between the length of the queue and authorzaton. In order to elmnate the USR furthest, we proposed a mechansm, t was shown as follows:

6 1) Whle the length of the authorzaton s equal to the report, there s no USR, the pollng wll be n order; 2)Whle the length of the authorzaton s greater than the report, recordng the USR and passng t on to the next OU and go to the next cycle of pollng; 3) Whle the length of the authorzaton s less than the report, that s the authorzaton can t satsfed wth the requrement of the queue and the authorzaton wll be n progress after re-send reports. Takng the j th class of busness n the th OU among the m th cycle for an example, the process of the pollng of ths mechansm we mentoned above s shown n fgure 6: In the fgure, BR ( m ) s for the sze of the bandwdth of the th OU among the m th cycle, L j B ( m) s for the length of the queue of the j th class of busness of the th OU among the m th cycle, BG ( m) s for the sze of the bandwdth of the authorzaton of the th OU among the m th cycle. Smulaton and Analyss We use the dynamc bandwdth allocaton model based on Agent and the algorthm based on barganng game to select the OU Agent n ths paper for smulaton. We dd the experment under the condtons that the load of the system s full and the length of the cycle s 1.25ms.We count the elmnaton tmes of USR about the mechansm n ths paper and document 8,the results s shown n Table 1. Table 1. The Comparson of the Frequency of USR Elmnaton n One Second between ths Text and Document 8. Tme(s) Our mechansm Mechansm n document 8 Tme(s) Our mechansm Mechansm n document Whle the length of the authorzaton s greater than the report, our mechansm can passng the USR on to the next OU Agent, but n the document 8,t wll be deleted drectly, so our mechansm can both mantan the sze of the cycle and mprove the effcency of the usage of bandwdth. Under the condtons that the load of the system s full and the length of the cycle s 1.25ms, We count the savngs of the bandwdth about the mechansm n ths paper and document 8, the result of the smulaton s shown n Fgure 7: Fgure 7. The Comparson of Bandwdth Savng.

7 Fgure 7 shows that the mechansm for USR elmnatng n document 8 can save about 2.5Mbps of the bandwdth, but when use the model we suggested, the number of the bandwdth savngs s about 4Mbps, t s greater than the mechansm mentoned n document 8. Summary In ths paper, we establshed a dynamc bandwdth allocaton model based on the thnkng of Agent, we establshed fve sub-agent: the busness Agent, SLA Agent, applcaton Agent, User Agent, user ratng Agent, and decomposed the affectng factors about the bandwdth allocaton among the OLT and OU layer by layer. It may enhance the ablty to descrbe the multple factors n the process of bandwdth allocaton. For the algorthm, we mproved the algorthm of IPACT based on ths model, ntroduced the dea of gamng and put forward a local redstrbuton algorthm based on bargan-bargan, regard the user level, delay, packet sze as a barganng condtons to sort the onlne users, t can enhance the effcency of elmnaton about USR. Accordng to the result of the smulaton, the effcent of elmnaton about USR s sgnfcantly better than the tradtonal mechansm. Reference [1]Yeoul S., Lee S., Lee Tae-Jn, et al. Double-phase pollng algorthm based on parttoned OU subgroups for hgh utlzaton n EPOs [J]. Journal Optcal Communcaton etwork, 29(5): [2]Chen Yong, Xong Yng, Lu Hu. Research on network bandwdth allocaton technology based on three networks convergence [J].Vdeo Engneerng, 212, 36(11): [3]Lang Gen, Lang Huomn, et al. Dynamc bandwdth allocaton algorthm for mult lnk delay optmzaton. [J]. Applcaton Research of Computers, 212, 29(1): [4]Zhang Jnyu, Lu L. The mplementaton mechansm of dstrbuted dynamc bandwdth allocaton based on utlty EPO [J]. Journal of Software, 28(7): [5]Ja Je, L Yanyan, Chen Jan, et al. Power control and channel allocaton n cogntve wreless mesh networks based on dfferental evoluton [J]. Acta Electronca Snca, 212(1): [6]L Xong. Agent-based Warfare Modelng [D]. atonal Defense Industry Press: [7]McGarry M., Resslen M., Maer M. Ethernet passve optcal network archtectures and dynamc bandwdth allocaton algorthm [J]. IEEE Communcatons Surveys & Tutorals, 28(3): [8]Chen B., Chen J.J., He S.L. Effcent and fne schedulng algorthm for bandwdth allocaton n Ethernet passve optcal networks [J]. IEEE Journal of Selected Topcs In Quantum Electroncs, 26(4):