SENSEFUL an SDN-based Joint Access and Backhaul Coordination for - - PowerPoint PPT Presentation
SENSEFUL an SDN-based Joint Access and Backhaul Coordination for Dense Wi-Fi Small Cells Eduard Garcia-Villegas , David Sesto-Castilla , Sven Zehl , Anatolij Zubow , August Betzler and Daniel Camps- Mur
Telecommunication Networks Group
The
an SDN-based Joint Access and Backhaul Coordination for Dense Wi-Fi Small Cells
Eduard Garcia-Villegas ∗ , David Sesto-Castilla ∗ , Sven Zehl † , Anatolij Zubow † , August Betzler ‡ and Daniel Camps-Mur ‡
‡ i2CAT Foundation, Spain {daniel.camps, august.beztler}@i2cat.net † Technische Universität Berlin {anatolij.zubow, zehl}@tu-berlin.de ∗ Universitat Politècnica de Catalunya {eduardg, dsesto}@entel.upc.edu
TKN TKN
TheSENSEFUL: General Scenario
Dense Small Cell network deployments
Considered one of the main strategies to face current growth
Poses many interesting challenges
Wi-Fi technology
Ubiquitous technology with important role in future 5G
deployments
TKN TKN
TheMotivation
Management of dense small cell deployments
Wired backhaul is not always possible wireless backhaul.
Access network (AN) and backhaul (BH) may share radio
resources
Increased traffic dynamics (e.g. increased handover frequency)
SDN as key technology to promote adaptability
TKN TKN
TheSENSEFUL: Objectives
Joint SDN-based management of Wi-Fi Access
Network and Backhaul Network
Backhaul-aware access network control
Status of backhaul influences QoS offered to STAs Network controlled association and handover entails
creation/modification of optimal backhaul network paths
Access/Backhaul resource management
Centralized scheduling of access network and backhaul network
links using hybrid TDMA/CSMA access scheme
TKN TKN
TheSENSEFUL: Objectives
Joint SDN-based management of Wi-Fi Access
Network and Backhaul Network
TKN TKN
TheSENSEFUL: Objectives
Joint SDN-based management of Wi-Fi Access
Network and Backhaul Network
Backhaul-aware access network control
Status of backhaul influences QoS offered to STAs Network controlled association and handover entails
creation/modification of optimal backhaul network paths
Access/Backhaul resource management
Centralized scheduling of access network and backhaul network
links using hybrid TDMA/CSMA access scheme
TKN TKN
TheSENSEFUL: Concepts I
Small Cell “boxes”
Multiple Wi-Fi
interfaces for access and/or multi-hop wireless backhaul
TKN TKN
TheSENSEFUL: Concepts II
Small Cell “boxes”
Multiple Wi-Fi
interfaces for access and/or multi-hop wireless backhaul
Independent
Controllers
Logical entities SDN paradigm
TKN TKN
TheSENSEFUL: Concepts III
Small Cell “boxes” Independent
Controllers
Enables:
Multi-tenancy (AN and BH with different owners/operators) Independent evolution of AN and BH technologies Control plane scalability (AN and BH functions are decoupled) Joint AN/BH resource
balancing, energy efficiency, resiliency, etc.)
TKN TKN
TheSENSEFUL: Small Cell Backhaul
SDN
architecture to enable Openflow based forwarding in wireless mesh networks using Linux [1]
[1] A. Hurtado-Borràs, J. Palà-Solé, D. Camps-Mur and
wireless backhauling for Small Cells," ICC 2015
TKN TKN
TheSENSEFUL: Access Network
Access Network based on BigAP approach [2]:
BigAP Soft Handover approach:
Enables infrastructure controlled seamless handover
Seamless Load Balancing Seamless client STA mobility support Controlled steering of client association
BigAP exploits the 802.11 DFS functionality and leads the
STA to believe that the serving AP will perform a RF channel switch due to a detected radar signal:
BIGAP works with unmodified STAs, i.e. support of
802.11n/ac is sufficient.
[2] A. Zubow, S. Zehl and A. Wolisz, "BIGAP — Seamless handover in high performance enterprise IEEE 802.11 networks," NOMS 2016
TKN TKN
TheSENSEFUL: Backhaul-aware access network control
Access Network / Backhaul control interface based on
REST API:
AN BH: POST new STA to inform of new association. BH
responds with metric of its capacity through that AP
Can be used to decide the best candidate AP for a given STA,
based on the status of the BH.
AN BH : PUT new station association information to inform
AN BH : DELETE station. BH AN : POST a suggested handover in order for the BH
controller to notify congestion
TKN TKN
TheSENSEFUL: Access Backhaul Resource Management
Share resources (ISM band) through centralized
scheduling using hybrid CSMA/TDMA (ath9k-hMAC [3, 4])
Reduce collisions (reduce contenders per slot and detect/avoid
hidden nodes)
Precise QoS policies Network Slicing [3] S. Zehl, A. Zubow and A. Wolisz, "hMAC: Enabling Hybrid TDMA/CSMA on IEEE 802.11 Hardware,"arXiv preprint arXiv:1611.05376 2016 [4] https://github.com/szehl/ath9k-hmac
TKN TKN
TheSENSEFUL: Testbed Experiments
Prototypical Implementation of SENSEFUL with
experiment setup:
AP/BH X
Backhaul / Access Node Setup:
INTEL NUCs (i5@1.3GHz, 4GB RAM)
2x Atheros IEEE 802.11n NICs, ath9k-hmac 1x ethernet for remote experiment
Client STA Setup:
TP-Link WDR4300
Samsung Galaxy Tab S2 (COTS / DFS Support)
TKN TKN
TheSENSEFUL: Testbed Experiments
Features under test:
Association/handover decisions based on backhaul status
Backhaul capacity to detect congestion and suggest favorable
handovers
Creation of optimized backhaul flows upon notification from access
network controller
Centralized TDMA scheduling to fairly distribute resources between
access network and backhaul network
TKN TKN
TheSENSEFUL: Testbed Experiments
Exemplified through a sequence of events (storyline):
Compared against a “legacy” approach (no cooperation between
access and backaul network)
Measured in terms of downlink (TCP) throughput and (Jain) fairness
TKN TKN
The
STA1 is switched on (only reaches AP1)
ANc handles association and notifies BHc (AP1)
BHc computes optimal path from STA1 to core
17
SENSEFUL: Results step by step
STA2 is switched on (sees AP1 and AP2)
ANc handles association and notifies BHc (AP2)
BHc computes optimal path from STA2 to core
0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 5 10 15 20 25 30
fairness index Throughput [kbps] time [s]
fairness SENSEFUL fairness legacy 0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 5 10 15 20 25 30
fairness index Throughput [kbps] time [s]
fairness SENSEFUL fairness legacy
STA3 is switched on (only reaches AP3)
ANc handles association and notifies BHc (AP3)
BHc computes optimal path from STA3 to core
SENSEFUL approach activates hMAC (TDMA)
Proportional to carried flows
0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 5 10 15 20 25 30
fairness index Throughput [kbps] time [s]
fairness SENSEFUL fairness legacy
TKN TKN
The
STA4,5,6 switched on (only reach AP2)
ANc handles associations and notifies BHc (AP2)
BHc computes optimal path from STAs to core
SENSEFUL reconfigures TDMA slot assignments
18
SENSEFUL: Results step by step
SENSEFUL requests a handover
BHc detects congestion and suggests ANc to move STA2
ANc decides handover and notifies BHc (AP1)
BHc computes new optimal path from STA2 to core
SENSEFUL reconfigures TDMA slot assignments
0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 5 10 15 20 25 30
fairness index Throughput [kbps] time [s]
fairness SENSEFUL fairness legacy 0.2 0.4 0.6 0.8 1 1000 2000 3000 4000 5000 5 10 15 20 25 30
fairness index Throughput [kbps] time [s]
fairness SENSEFUL fairness legacy
TKN TKN
The19
SENSEFUL: results step by step
TKN TKN
The Joint management of access network and
backhaul network show benefits even in a simple scenario
Network-driven association control helps in
reducing backhaul network bottlenecks
Information from backhaul network helps in
providing better association decisions (better for STAs and for backhaul network)
The use of TDMA-like access improves fairness
Negative impact on throughput with few competing
STAs (worse than legacy CSMA/CA)
Enables multiple network configurations
Differentiate services, Network slicing
20
SENSEFUL: Conclusions
TKN TKN
The TKN TKN
TheSENSEFUL: Access Network - BigAP HO
Gateway
AP1
(ch=1)
AP2
(ch=2)
STA
Serving: Target: BIGAP controller
1. Decision by controller to
handover STA from AP1 to AP2.
2. Traffic flows towards STA need
to be routed over AP2.
3. Controller associates and
authenticates STA on the target AP
is properly registered within AP2.
4/5. Controller instructs AP1 to send
a unicast beacon containing a CSA-IE with the channel set to the target AP, here 2, destined to STA.
notice that it is being served after the channel switch by another AP, AP2. STA continues with its communication.
1 2 3 4 5 6 7
TKN TKN
The23
SENSEFUL: results step by step