Simulation Scenario for Unplanned Wi-Fi Network

1. Simulation Scenario for Unplanned Wi-Fi Network Date: 2013-09-16 Authors: Minho Cheong (ETRI)

2. Abstract This presentation gives set of issues in designing simulation scenario for unplanned Wi-Fi network. Minho Cheong (ETRI)

3. Structure of Simulation Scenario for HEW [4] • Observation in terms of unplanned Wi-Fi • Coupling between planned and unplanned is just at macro-level • Only residential is considered as unplanned • Random positioning applied only by which we cannot model the realistic environments Minho Cheong (ETRI)

4. Characteristics of Unplanned Wi-Fi • In all cases • (1) Unexpected position • Position of each AP is at customer’s own. Nobody knows. • (2) Unexpected active-time • Turn-on/turn-off of the AP is hardly expectable • (3) Unexpected increase in deployment • Nobody knows who newly installed AP’s in the neighborhood • (4) Uncontrollable • Wi-Fi controller cannot touch • Many low-featured AP cannot even decode the high-featured signaling • (5) Including low-featured AP’s • Most people still hesitate to buy high featured ones as private AP’s Minho Cheong (ETRI)

5. Characteristics of Unplanned Wi-Fi • In worst cases, additionally • (6) Invisible • AP’s SSID hidden while existing by customer’s setting • (7) Moving • Tethering devices (soft AP) can be moving Minho Cheong (ETRI)

6. Importance of Unplanned Scenario in HEW • Crucial reason why current Wi-Fi is so degraded • Almost 100% of Wi-Fi environments in the real world are affected • Purely planned Wi-Fi scenario hardly exists • There are no remote & safe Wi-Fi zone without any private AP • It is hardly possible to exterminate private AP’s even in a well-planned Wi-Fi environment • This is the very environments under which HEW tries to put its major effort to enhance the network performance Minho Cheong (ETRI)

7. Importance of Unplanned Scenario in HEW • Unplanned Wi-Fi exists everywhere as significant • Not only in the residential environments • Example #1 (indoor hot spot) • Measurement done at an underground mall (COEX in Seoul) • 44 % of all the detected AP’s near by are private AP’s • Per-STA AVG. throughput is only 3.7Kbps mainly due to private AP’s • While 11b/11g/11n can support max. PHY 11Mbps/54Mbps/600Mbps Minho Cheong (ETRI)

8. Importance of Unplanned Scenario in HEW • Unplanned Wi-Fi exists everywhere as significant • Not only in the residential environments • Example #2 (outdoor hot spot) • Measurement done at a train station (KTX station in Seoul) • 18 % of all the detected AP’s near by are private AP’s • Per-STA AVG. th’put is only 13.2 Kbps mainly due to private AP’s • While 11b/11g/11n can support max. PHY 11Mbps/54Mbps/600Mbps Minho Cheong (ETRI)

9. What We Expect from Unplanned Scenario • First, we want to check the network performance of real-world unplanned Wi-Fi network itself • Second, we really want to check the impact of unplanned Wi-Fi AP(s) which permeate the well-planned network on it • In order to quantitatively check how much degraded the network performance goes when one or limited number of bad guys (private AP’s) are talking in the network • In order to quantitatively check how much gain we can achieve when some suggested technology (PHY or MAC) applied to the high-featured AP’s (connected to Wi-Fi controller) in the original well-planned network with small number of private AP’s Minho Cheong (ETRI)

10. How to Design Unplanned Scenario • Coupling at micro-level or at macro-level? • When coupling with a well-planned Wi-Fi network to find out impact of unplanned Wi-Fi • (1) Coupling at macro-level • Multi-BSS unplanned Wi-Fi “network” + planned network • Only assuming that an apartment building is near by a football stadium • (2) Coupling at micro-level • Each private Wi-Fi APpermeates a planned network • Assuming that individual private AP may exists even in the planned • It seems that coupling with a planned network at micro-level is more realistic and more matched to the purpose of HEW • We need to define derived scenarios from the original planned one by introducing some private AP’s in it. Minho Cheong (ETRI)

11. How to Design Unplanned Scenario • AP’s with the same age or different ages? • In a well-planned network, all the AP’s are usually provided at one time by one provider so that all the AP’s are in the same generation • e.g. our library Wi-Fi network has only 802.11n AP’s in it • But, unplanned Wi-Fi is likely to have several generations of AP’s in the neighborhood • So, my 802.11n AP doesn’t work so well due to neighbor’s 11b AP • So, we need to allow several generations of AP’s in designing of unplanned Wi-Fi Minho Cheong (ETRI)

12. Suggestion Minho Cheong (ETRI) • 2 levels of coupling with unplanned Wi-Fi • coupling at micro-level : <managed network under attack> • coupling at macro-level : <managed network + unmanaged network overlaid> • Multi-generations of private AP’s applied (green)

13. References [1] 11-03-0802-23-000n-usage-models [2] 11-13-0840-01-0hew-HEW-functional-requirements-follow-up [3] 11-13-0556-01-0hew-wi-fi-interference-measurements-in-korea [4] 11-13-1000-01-0hew-simulation-scenarios Minho Cheong (ETRI)