Automated testing of congestion within the UMTS cellular

Agenda • Introduction • Current Situation • Network architecture • Congestion Areas • What

Introduction • As the amount of 3 G subscribers grow, grows the need for

Current Situation • We have an automated system capable of many network scenarios •

Network architecture – Release 99 5 © 2007 Nokia Masters Thesis Seminar. ppt /

Congestion Areas within the scope of thesis • Code Tree congestion • Shortage of

What was done? 1/2 • In thesis it was studied what is needed for

What was done 2/2 • The testing was concluded possible in a following manner:

Conclusions • Testing of congestion control possible with the automation tool • Testing possible

Next Steps • The work was focused on stationary mobile scenarios Ø Mobility issues

Thank you ! References: Review of RNC Interfaces and Architecture, by Mikko Nieminen, training

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Automated testing of congestion within the UMTS cellular network Masters’ Thesis Seminar Claes Kaarni Prof Riku Jäntti 7. 3. 2007 Tietoliikennelaboratorion neuvotteluhuone SE 208 b 1 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CK

Introduction • As the amount of 3 G subscribers grow, grows the need for more accurate network dimensioning and more efficient congestion control in UMTS cellular networks → congested situations will be unavoidable in dense population areas • operators want to optimize their network dimensioning to minimize costs → effective congestion control functions and mechanisms → direct savings for the operators • Verification of congestion control functions and mechanisms is demanding • Can implementation of this be tested with automation? 3 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

Current Situation • We have an automated system capable of many network scenarios • Automated system capable of repetitive test case execution • The automation tool has several interfaces with several elements acting in a testing environment • Interface with testing UE • Interface with the RNC • Interface with attenuator system • Interface with a Load Generator • The focus of thesis was to study what is needed for testing congestion control with this tool 4 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

Congestion Areas within the scope of thesis • Code Tree congestion • Shortage of spreading codes in the Code Tree • BTS HW congestion • Shortage of BTS internal processing resources • Iub transmission capacity congestion • Shortage of transmission capacity between BTS and RNC • Air interface congestion • Shortage of interference capacity in the air interface 6 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

What was done? 1/2 • In thesis it was studied what is needed for testing congestion control with the automation tool in particular • The work was carried out by studying two congestion control features • One for real-time traffic management • One for non-real-time traffic management • The main principle of the congestion control features: • Downgrading or releasing NRT users • Releasing lower priority RT users 7 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

What was done 2/2 • The testing was concluded possible in a following manner: • The automation tool verifies test case wanted to be executed • The automation tool might perform precondition changes into the test environment • A specific load is created into a cell with the load generator • The automation tool starts to penetrate defined connections into the congested network • After execution logs are collected analyzed 8 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

Conclusions • Testing of congestion control possible with the automation tool • Testing possible to some extent but not at same detail as in manual testing • Testing of congestion control of real-time traffic was possible on a high level of detail • Real-time services have stringent requirements → Simple and clear procedures • Testing of congestion control of non-real-time traffic was possible but is considered as more demanding • Scheduling flexible • A big challenge to verify that correct connection is chosen as candidate for making room for the higher priority connection wanted to be established 9 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

Next Steps • The work was focused on stationary mobile scenarios Ø Mobility issues a great area of interest Ø Soft and softer handovers Ø Inter-RNC handovers, Inter-frequency handovers, Inter-system handover • The work relies on searching for errors from user-perspective and network internal signaling Ø Monitoring of network counters should be developed as a new dimension for testing 10 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CKa

Thank you ! References: Review of RNC Interfaces and Architecture, by Mikko Nieminen, training material, 2006 Internal document about automation system, 2006 11 © 2007 Nokia Masters Thesis Seminar. ppt / 2007 -03 -07 / CK