Dynamic control method of queuing delay with/without OEO conversion - PowerPoint PPT Presentation

Dynamic control method of queuing delay with/without OEO conversion in a multi stage access network a multi-stage access network 2012 3 6 2012.3.6 Tatsuya Shimada Noriko Iiyama Hideaki Kimura Tatsuya Shimada, Noriko Iiyama, Hideaki Kimura and Hisaya Hadama NTT Access Network Service Systems Laboratories C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

Outline 1 Background 2 Network configuration g 3 Dynamic control method of queuing delay 4 Characteristics and parameter setup 5 Summary C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

1 Background - - Future services - - Various services must be supported in future access network. The future access network must support various aspects of QoS such as pp p Q bandwidth and delay performance that each service requires. TMS (Tiny bandwidth Mass Service), BCS (Broadband Consumer Service). HBS (Huge bandwidth Service) HBS (Huge bandwidth Service) New service TMS dom ains Mass ( Categories) ( Categories) RFID tags sensors Number of BCS actuators HBS networked Interactive video etc. terminals terminals com m unication, com m unication di iti digitization of ti f circulation of CGM, cloud- Huge data center, high quality various events in com puting,CDN etc. com m unication with realistic the real world. sensation etc. Small Ti Tiny H Huge Communication Current netw ork services bandwidth ( VoI P, W eb, P2 P etc.) Fig.1 Classification of network services in the future Fig 1 Classification of network services in the future （ Ref ） http://www.itu.int/ITU-T/focusgroups/fn/output.html#2nd C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

Future network ITU-T Y.3001 (2011/5) Future Networks : Objectives and Design Goals C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

Challenge ① The queuing buffer size must be designed according to peak rate. g g p O O L L T T W W D D M M - - P P O O N N R R o o u u n n d d R R o o b b i i n n O O N N U U # # 1 1 P P D D # # 1 1 B B u u f f f f e e r r # # 1 1 A A A A g g g g g g g g r r r r e e e e g g g g a a a a t t t t i i i i o o o o n n n n O O N N U U # # 2 2 P P D D # # 2 2 B B u u f f f f e e r r # # 2 2 L L D D … … … … … … … … O O N N U U # # N N P P D D # # N N B B u u f f f f e e r r # # N N Traffic fluctuation ② The procedure of reading out upstream Huge g signals at the queuing buffer becomes g q g exceedingly complex to support QoS metrics like latency. Tiny Tiny Time C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

Multi-stage access network New access network with multi-access points and multi-service planes supporting quality (bandwidth, delay performance) of each service. aggregation Service #N Access Point#N drop add (OLT#N) … aggregation regenerate Service #2 A Access Point#2 P i t#2 (OLT#2) drop regenerate add aggregation regenerate regenerate Service #1 regenerate Each user add Each user drop Access Point#1 (OLT#1) (OLT#1) Merit: low delay performance, avoiding traffic congestion … C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

(Reference) Elastic OLT technology Various distance without OEO TMS BPS HBS (reference) Special Feature: “Towards Ultrahigh-speed High-capacity Networks” (reference) Special Feature: Towards Ultrahigh-speed High-capacity Networks NTT Technical Journal, vol.7, no.5, May 2009. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

2 Network configuration -- upstream OLT -- 【 Upstream OLT 】 Checking header information information Header Matched signals Plane#N PD Buffer Drop Buffer Control FDL Access SOA ONU Point Corresponds to time Corresponds to time E Erase matched h d ON ON of checking header signals OFF OFF If the signals match a service, the matched signals are sent to a drop buffer. The control part turns the SOA bias OFF and erases the matched signal. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

2 Network configuration -- upstream OLT-- 【 Upstream OLT 】 Checking header information information Header Plane#N PD Buffer Drop Buffer Control FDL Access SOA ONU Point Corresponds to time Corresponds to time ON ON ON Regenerates NOT of checking header matched signals OFF OFF If the signals do not match a service, the unmatched signals are sent to the next access point. The control part turns the SOA bias ON for regeneration. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

2 Network configuration -- downstream OLT -- 【 Downstream OLT 】 A downstream OLT needs a function for added signals NOT added signals Add Buffer Header No modulation No modulation Control C t l PD Buffer FDL EDFA ONU SOA MOD Access Point Point Corresponds to time of checking header Regenerates all signals If no signals are present in the add buffer, all the signals are regenerated in the SOA. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

2 Network configuration -- downstream OLT -- 【 Downstream OLT 】 Add Buffer Add Buffer added signals Header Control buffer signals buffer signals PD Buffer added signals FDL EDFA ONU SOA MOD Access Point Erase signals with data Erase signals with data Modulate buffer signals rewrite technique and added signals If signals are present in the add buffer, the downstream signals are erased by SOA optical saturation using a data rewrite technique. Then the buffer signals and added signals are modulated. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

(Reference) data rewrite technique Erase signals with SOA optical saturation region optical saturation region CW S. Narikawa et al., “Gbit-class transmission using SOA data rewriter for WDM-PON,” pp.399-408 IEICE TRANS COMMUN., vol.E91-B, No.2 Feb. 2008. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

3 Dynamic control method of queuing delay The system cannot control the number of OEO conversions because the transmission of downstream signals with or without OEO conversions depends transmission of downstream signals with or without OEO conversions depends on the bandwidth of the added signals and the changes caused by the fluctuation of this bandwidth. Therefore, the system cannot satisfy the delay performance requirements of each service performance requirements of each service. Add Buffer With OEO conversion Control PD Buffer FDL EDFA EDFA SOA MOD Without OEO conversion C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

3 Dynamic control method of queuing delay Token packet method <Decision Criterion> frame length > the total number of token : without OEO conversion (O/O mode) frame length < the total number of token : with OEO conversion (O/E/O mode) Checking part g p B add : bandwidth of added signal Controller Add Buffer T: cycle R: the number of tokens PD Buffer Token0: initial value L opt : frame length Total number of tokens FDL subtracted tokens EDFA SOA SO B opt : bandwidth of downstream signal C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

3 Dynamic control method of queuing delay 【 Control#1 】 Token criteria + status of collision When the downstream signal does not collides with added d t llid ith dd d signal, the downstream signal can be transmitted in the O/O mode even if the total number of tokens is smaller than frame length. g C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

3 Dynamic control method of queuing delay 【 Control#2 】 Only Token criteria If th If the total number of tokens t t l b f t k is larger than frame length of the just received downstream signal, the added signal waits even if it arrived before the downstream signal. At the same time, the downstream signal can be transmitted in O/O mode. O/O mode. C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

4 Characteristics and parameter setup To investigate the characteristics of each token parameter (R, T, and Token0) and how to set up these parameters to achieve the ) p p required number of OEO conversions, we estimated the OEO conversion ratio, the ratio of the number of downstream signals sent under O/E/O mode to the total number of downstream signals. <Simulation parameter> Transmission rate : 1 Gbit/s Optical packet bandwidth (B opt ) : 250Mbit/s, 500Mbit/s Added signal bandwidth (B add ) : 250Mbit/s, 500Mbit/s F Frame length L opt : 64-1518 bytes l h L 64 1 18 b (Header length : 14 bytes , Data length : 46-1500bytes, frame check sequence : 4 bytes) Model : Poisson process M d l P i C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n

4 Characteristics and parameter setup 【 Control#1 】 Token criteria + status of collision C o p y r i g h t ( c ) 2 0 1 2N T T C o r p o r a t i o n