Mobile Core Network Redimensioning for Efficient

Resource UtilizationEyuphan Bulut (VCU)

Abhimanyu Gossain (BBN)Perfecto 2017

(Infocom Workshop)

Mobile Data Tsunami• Responses • Building new base stations and/or deploying femtocells• Improving radio technology and bandwidth (ex: LTE or 4G)• Applying tiered price plans on data usage• WiFi offloading

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MotivationWith WiFi Offloading:• Mobile Network Operators (MNO) lost visibility and

control over user data

Thus:• MNOs added new gateways to core network to:• Provide services over WiFi/femto• Manage the offloading

Result:• Core network load did not change• Benefit of WiFi offloading is only for cellular space

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Mobile Core Network

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IPNetwork

SGW PGW

MME

SGSN GGSN

CoreNetwork(CN)

eNodeB

NodeB MSC

RNC

RadioAccessNetwork(RAN)

4Gcore

3Gcore

PublicDataNetwork(PDN)

UE

Extended Mobile Core Network

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IPNetwork

SGW PGW

MME

SGSN GGSN

CoreNetwork(CN)

eNodeB

NodeB MSC

RNC

RadioAccessNetwork(RAN)

4Gcore

3Gcore

PublicDataNetwork(PDN)

UE

H(e)NBGW

ePDG

SaMOG

Untrusted

Trusted

Femtocell

Carrier-control-free

MotivationTwo problems in current usage:• Low user session utilization (sending data) and waste in

the number of sessions• Uneven data usage (diurnal) distribution during a day

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0%

20%

40%

60%

80%

100%

0 5 10 15 20

%ofu

sers

Hour(oftheday)

%active(Carrier#1)%attached(Carrier#1)%active(Carrier#2)%attached(Carrier#2)

NotutilizedSessionCapacity

0

1

2

3

4

5

6

0 5 10 15 20

DataRatepe

rSessio

n(kbp

s)

Hour(oftheday)

AverageDataRateWeekdaysWeekend

Max

Average

1.55x

Carrier#2

Proposed SolutionsGoal 1: Efficient session utilization without

• waste in session count• decrease in subscriber count• interruption in user activity

Solution 1: Session Aggregation through Social Offloading Groups (SOG)

• Decreasing cellular connection to PGW

Goal 2: Balanced utilization of gateway (CPU) resources Solution 2: Core Network Collaboration

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Social Offloading Group (SOG)Proposed Model• Group close users (e.g., family members) and provide

one cellular connection to core

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Macrocell

SOGlead

sameuser

Home SOG

Work SOG

t1 t2

D2Dlink

Cellular

Leadassignment/rotation

Questions:• How to form groups?• Selection of lead and

rotation• Core related management

(e.g. paging)

Social Offloading Group (SOG)Energy oriented lead selection:- Select the group member who can minimize the energy

consumption for the group

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The energy node j consumes to complete the task i

energy consumed in promotion from idle to DCH state

energy consumed in tail state

cellular bandwidth of node k

local bandwidth between nodes j and k

Data similarityData

size

sending directly

sending over k

Lead selection

Collaboration of Core Networks• Diurnal behavior

• Gateways should have capacity for the highest

• How to change user behavior?• Examples:

• Tiered pricing,• Incentives for data usage in less peak

times

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0

1

2

3

4

5

6

0 5 10 15 20DataRatepe

rSessio

n(kbp

s)

Hour(oftheday)

Idea: Utilize time zone difference and coordinate multi-core network traffic

Collaboration of Core Networks

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S8

S8

S5

S8

SGW PGW

Mob

ilecore#1

SGW PGW

SGW PGWS5

SGW PGWS5

Mob

ilecore#3

Mob

ilecore#4

Mob

ilecore#2

S5

0

1

2

3

4

5

6

0 5 10 15 20DataRatepe

rSessio

n(kbp

s)

Hour(oftheday)

Core#1 Core#2Core#3 Core#4

0

1

2

3

4

5

6

0 5 10 15 20

DataRatepe

rSessio

n(kbp

s)

Hour(oftheday)

AverageCore#1

Heavy user traffic could be directed for easiness

Collaboration of Core Networks• Potential saving up to 40-50%

Issues:• Delay?• Multi-MNO management• Trust/privacy management

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0%5%10%15%20%25%30%35%40%

0 1 2 3 4 5 6 7 8 9

Capa

cityincrease(%

)Hourdifferencebetweencoretimezones

2collaboratingcores3collaboratingcores4collaboratingcores

Future/Ongoing Work• Solutions to be tested over GENI wireless testbed

• GENI: Global Environment for Network Innovations• LTE deployment over 12 campuses

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Thank you!

Questions?