achieving carrier-grade wi-fi in the 3gpp world

8/12/2019 Achieving carrier-grade Wi-Fi in the 3GPP world

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Achieving carrier-gradeWi-Fi in the 3GPP worldUsers switch between cellular and Wi-Fi networks regularly. The process is not always as seamlessas it could be, sometimes requiring several painful steps. Hotspot 2.0 is starting to change all that.

Release 2 and in the ANDSF enhance-ments in 3GPP Rel 12.

The Hotspot 2.0 standard uses operator-provided information stored in a sub-

scribers SIM to automate the search foravailable networks and the associatedlogin procedure removing the need forcumbersome manual steps, and improv-ing user experience. However, the deci-sion to switch is still determined by thedevice. To implement Wi-Fi that is trulycarrier-grade, control needs to be hand-ed back to the network operator.

The existing 3GPP ANDSF standardprovides operators with a mechanismfor handling traffic on public data net-

works. Operators can list their preferrednetworks and provide policies for how

subscriptions and explosive growthin demand for mobile broadband.Numbering 6 billion at the end of 2011,mobile subscriptions are expected to hit

the 9 billion mark by the end of 20174.Mobile-data usage is expected to grow15 times between 2011 and 20174. To pro-vide this massive number of users withgood service, Hotspot 2.0 will build onthe roaming principles that have suc-cessfully supported global growth in themobile industry.

Now that the first phase of the initia-tive Hotspot 2.0 Release 1 has beenlaunched, Ericsson and other telecomvendors are setting their sights on thenext step network-directed roaming,which will be developed in Hotspot 2.0

STEPHEN RAYMENT AND JOAKIM BERGSTRM

BOX A Terms and abbreviations

AAA authentication, authorization

and accounting

AC access controller

AES Advanced Encryption Standard

ANDSF access network discovery and

selection function

ANQP Access Network Query Protocol

AP access point

BNG Broadband Network Gateway

BPCF Broadband Policy Control Function

BSS Business Support Systems

CAPWAP Control and Provisioning of Wireless Access Points

CoA Change of Authorization

DPI deep packet inspection

DSMIPv6 Dual-stack Mobile IPv6

EAP Extensible Authentication Protocol

EAP-AKA EAP-Authentication and

Key Agreement

EAP-TLS EAP-Transport Layer Security

EAP-TTLSEAP-Tunneled TLS

EPC Evolved Packet Core

EPS Evolved Packet System

ePDG Evolved Packet Data Gateway

GBA Generic Bootstrapping Architecture

GTP GPRS Tunneling Protocol

HESSID Homogenous Extended Service Set ID

HLR home location register

hPCRF home PCRF

HSS Home Subscriber Server

IKEv2 Internet Key Exchange version 2

IP-CAN IP connectivity access network

IPsec IP Security

I-WLAN interworking wireless LAN

ISMP inter-system mobility policies

LBO local breakout

LI Lawful InterceptionMCC Mobile Country Code

MNC Mobile Network Code

MO management object

MSCHAP Microsoft Challenge Handshake

Authentication Protocol

NAI network address identier

NGH Next Generation Hotspot

OCS online charging system

OFCS ofine charging system

OMA-DM Open Mobile Alliance

Device Management

PCRF policy and charging rules function

PDN GW packet data network gateway

PLMN Public Land Mobile Network

PMIP Proxy Mobile IP

PMIPv6 Proxy Mobile IPv6

RAT radio-access technology

RF radio frequency

SaMOG S2a mobility-based on GTP

SSID Service Set Identier

TWAN trusted WLAN access network

UAM Universal Access Method

UE user equipment

USIM Universal Subscriber Identity Module

vPCRF visited PCRFWAN wide area network

WAG wireless access gateway

WBA Wireless Broadband Alliance

WFA Wi-Fi Alliance

Wi-Fi trademark of the Wi-Fi Alliance

WISPr Wireless Internet Service

Provider roaming

WLAN wireless local area network

WPA2 Wi-Fi Protected Access v2

XML Extensible Markup Language

Shortly after the close of the

2012 Mobile World Congress,

the GSMA announced a plan to

collaborate with the Wireless

Broadband Alliance (WBA) tosimplify Wi-Fi-hotspot access

for smartphones and tablets1.

Intended to provide subscribers

with seamless cellular-to-Wi-Fi

roaming, this joint GSMA/WBA

initiative is based on the WBA

Next Generation Hotspot (NGH)

program2and the Wi-Fi Alliance

Passpoint certifcation3 known

in the industry as Hotspot 2.0.

The need for such an initiative hasrisen out of the rapid rise in mobile

ERIC SSO N REVIEW 2012

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to use them. For the moment, this infor-mation is relatively static and is pre-pared without taking real-time network

conditions into consideration.The goal is to enable carrier-grade

Wi-Fi that provides a secure andseamless experience for users, whereroaming to and from 3G/LTE to Wi-Finetworks is operator-controlled andnetwork-directed. To fulfill this vision,Ericsson is working with the industry toalign both the Hotspot 2.0 Release 2 andANDSF specifications.

Vision for heterogeneous networks

As an integral part of the completemobile-broadband solution, Wi-Fi is

a key element of heterogeneous net-works. Just like any other radio-accesstechnology (RAT), Wi-Fi needs to be con-nected to the core network. Viewed inthis way, it can be used to deliver the fullsuite of services available on the cellulardata network, becoming more than justan offloading alternative for capacity-challenged networks.

Wi-Fi networks are consistently highperforming owing to their inherentsmall-cell architecture and their use ofwidely available unlicensed spectrum.Thus, adding Wi-Fi to the set of acces-

sible radios can help to optimize userexperience. But integration of Wi-Fiinto the cellular network, requires thata number of elements be considered:

pico base stations house Wi-Fi and mul-

timode small-cell licensed-band radios;

common network nodes perform aggre-

gation of cellular and Wi-Fi networks;

unied network management; and

many integrated back-end network ele-

ments, including HSS/HLR, OCS/OFCS

and PCRF/BCRF, enable unied services

and features.

The enablement of industry standard-

ization and solutions that push per-formance beyond standards to enableleading-edge services are importantaspects of the vision for fully integratedWi-Fi and cellular networks. Figure 1shows an architecture for interwork-ing Hotspot 2.0 access networks witha 3GPP-based core network using well-established protocols for access and corenetwork interworking. The architec-ture is based on Wi-Fi Alliance and 3GPPR11 specifications. For completeness,the illustration shows how untrustedWi-Fi (residential) can interwork with

the EPC, to, for example, support voicewhen only Wi-Fi coverage is available,however this is not elaborated furtherin this article.

Use case

The following use case is based on a typ-ical dual-mode smartphone scenariowhere a subscriber is using the cellu-lar data network of their service pro-

vider to browse the web while walkingaround a busy downtown area. The userenters a shopping mall where carrier

Wi-Fi coverage is available. As data usagein the area is high, the cellular networksignals the smartphone to switch toWi-Fi. The Wi-Fi radio in the smart-phone detects a Hotspot 2.0 access point(AP) which it queries, using the AccessNetwork Query Protocol (ANQP) to findout whether or not the users home net-

work can be reached through this Wi-Finetwork. If it can, the cellular networktakes the decision to switch the users

internet connection from cellular toWi-Fi, based on ANDSF-provisioned pol-icy for this location. Using the EAP-AKAmechanism, the smartphone switchesand starts authentication with the AAAserver of the cellular network usingthe users SIM card credentials. On suc-cessful authentication, the access con-troller (AC) sets up a GTP tunnel to thePDN GW to access a carrier-managed

connection to the internet, and the usercontinues to browse, enjoying goodservice performance.

Hotspot 2.0

The WFA, which is responsible for thecertification of Wi-Fi products, has cre-ated Hotspot 2.0 a technical specifica-tion that brings together a number ofindustry standards. Targeting serviceproviders in the hotspot Wi-Fi market,the specification tries to apply the sim-plicity of cellular roaming to Wi-Fi. Theprogram run by WFA is called Wi-Fi

HSS

HLR

PDN

GW

ePDGWAGGBA

PCRF

BPCF

BNG

AC

AP AP

AAA

ANDSFIMS

OCS

OFCS

External

IP networks

LBO

LBO

Untrusted

Wi-Fi

Wi-Fi

SWu

S14

SWxRx

Gy

SGi

Gz

Gx

RADIUSCoA

RADIUSDIAMETER

S9S9a

STa

CAPWAP

L2/L3

Auth

Auth

PolicyControl

Data

L2/L3

S2a

S2a

S2b

SWd

S6b

Trusted

Wi-Fi

FIGURE 1 Wi-Fi and 3GPP

3

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Table 1: ANQP information elements

ANQP elements

Service-provider identifcation

3GPP cellular network information

NAI realm list

Roaming consortium list

Hotspot identifcation

Domain name list

Venue name

Venue information

Operator-friendly name

Network characteristics

IP address-type availability

WAN metrics

Connection capability

Operating class

Network authentication type

Beacon frame elements

HESSID

Access network type

Internet available

BSS load

need to enter credential information

manually to establish a connection.Ericssons Virtual AP capability

already enables multi-operator roam-ing where a single hotspot broadcastsmultiple beacons (SSIDs) so that severalservice providers can offer connectionsto the same AP. The Virtual AP ensuresfull traffic-segregation and individualoperator-defined AAA rules and policyapplication. However, the multiple-SSIDapproach limits the maximum numberof roaming operators typically to eight and the transmitted beacons occupyexcessive amounts of radio airtime.

To establish a connection to theirpreferred provider automatically inHotspot 2.0, mobile devices can useANQP to determine which service pro-viders are available via a given hotspot.This protocol identifies providersthrough their MCC and MNC numbers,realm information or roaming consor-tium element, enabling a wide range ofroaming capabilities without having tobroadcast provider information.

Naturally, security is of great impor-tance. All Passpoint devices use WPA2-Enterprise security to authenticate and

CERTIFIED Passpoint, and Ericssonhas been a key contributor to it, provid-ing equipment as part of the certifica-tion test bed.

Today, connecting to a hotspot canbe an awkward and inconsistent expe-rience for subscribers who may needto go through several manual steps to

switch network. These steps can includesearching for a network, enabling a con-nection to that network and enteringaccount credentials by launching a webbrowser. Some mobile-device operat-ing systems, such as iOS, have alreadyautomated parts of the switching pro-cess using a captive portal method WISPr or UAM and some third-partyapplications called connection man-agers embed this capability. However,these solutions are only available for cer-tain devices, and are offered by a limit-ed range of carriers; they are far from

widespread.The aim of Hotspot 2.0 is to change

this supporting widespread automat-ic switching to Wi-Fi. As an industry-wide solution, Hotspot 2.0 will drivenetwork interoperability and standard-ized network association, authentica-tion, security, sign-up and policy controlfor mobile devices in a way that is com-pletely transparent to the user. Release1 completed in June 2012 specifiedthe capabilities for network discov-ery and selection, and secure authen-tication. Certified handsets and access

points supporting theses capabilities arenow starting to appear on the market.Release 2, planned for 2013, will includeadditional capabilities to deliver opera-tor policy to devices and enable imme-diate account provisioning.

Release 1

Network discovery and selection which enables mobile devices todiscover and select networks automat-ically without subscriber interven-tion is a key element of the initialrelease. Using ANQP (specified in theIEEE 802.11u-2011 amendment5) mobiledevices can query hotspots for a rangeof parameters that are useful in theprocess of selecting a network. Thecomplete list of information elementssupported by the protocol is providedinTable 1, and includes parameterssuch as the hotspot operators domain

name, the roaming partners accessi-ble via the hotspot and IP address-type(IPv4 or IPv6) availability. All of theseparameters are useful for determiningwhich available network best fits thesubscriber. There are several credentialtypes that can be used to grant a deviceaccess to the network, including:

SIM/USIM-based authentication, which

is widely used in cellular networks today;

a username-password key; and

certicate-based credentials for xed

operators and Wi-Fi-only devices.

In all these cases, users will no longer

Cellular Cellular

Wi-Fi

Data rate

[Mbps]

FIGURE 2 Wi-Fi selected over cellular

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secure the air link between the deviceand the hotspot. WPA2 uses four-wayhandshaking and AES encryption, offer-

ing a level of security that is comparableto cellular networks.

The Hotspot 2.0 specification sup-ports four standard protocols common-ly deployed in the industry:

EAP-SIM for devices with SIM

credentials;

EAP-AKA for devices with USIM

credentials;

EAP-TLS for use on both the client and

server side, with a trusted root certi-

cate; and

EAP-TTLS with MSCHAPv2 for user-

name-password credentials.

The specification adds to WPA2-Enterprise security by incorporatingfeatures to mitigate common attackthreats in public Wi-Fi deployments,including layer-2 traffic inspection, fil-tering and broadcast/multicast control.

Release 2

The second release of the specificationis currently being drafted addingoperator policy control and immediateaccount provisioning. The certificationprogram for this release is planned forlate 2013.

While Release 1 supports automaticnetwork selection based on user prefer-ences, pre-provisioned operator policy,and network availability, it does not sup-port the capability to deliver operator-specific policies this will be includedin Release 2.

Immediate account provisioning,also referred to as online sign-up, is astandardized and secure process thatenables new user accounts to be createdat the time of connection. By support-ing this process, a cross-vendor subscrip-tion-provisioning methodology can be

adopted for non-subscribers provid-ing, easy access to people using Wi-Fi-only (non-SIM) devices who have noother means of signing up, hence creat-ing value for the operator.

Shifting control

To ensure the best user experience,subscribers should be connected tothe most appropriate network giventhe time of day, their current locationand account preferences. To prioritizethe list of networks correctly for a giv-en user, the ability to apply operator

policies is essential. Operators needto be able to control whether a deviceuses cellular or Wi-Fi, and in the caseof Wi-Fi, which network would ensurethe best user experience. Users still havecontrol over when they connect to a res-idential or enterprise network by man-ually selecting the local Wi-Fi network.

Operator policy has been included forsome time in the 3GPP interworkingwireless local area network (I-WLAN)specification6. The ANDSF7mechanismprovides devices with additional infor-mation to expedite discovery and selec-

tion. Mobile WLAN devices use PLMNselection based on operator-definedpriorities that are preprogrammed intothe SIM to choose the appropriateoperator network6. Such priorities canbe further modified according to man-agement objects (MOs), as specified in3GPP TS24.2358.

The ANDSF mechanism augmentsPLMN selection, providing improvedcontrol over the network-access deci-sions made by devices. Through a set ofoperator-defined rules, ANDSF guidesdevices through the decision-making

process of where, when and how tochoose a non-3GPP network. Interactionbetween a device and the ANDSF serv-er uses the S14 IP interface, and data MOs in OMA-DM compatible XML can be transported over any availablenetwork. Typically, operator policiesare pre-stored in devices before theyare shipped. However, the controlling

ANDSF server can push policies to devic-es and devices can use the pull mech-anism to access policies at any time.When roaming, the ANDSF server ofthe visited network takes precedence.

When a device sends location informa-tion which may include geograph-ical, cellular area and WLAN SSIDdescriptors to the ANDSF server, dis-covery information is sent back to thedevice providing it with a list of alter-native access networks, such as a listof Wi-Fi network SSIDs within the cur-rent cell ID. At the same time, inter-system mobility policies (ISMPs) are sentto the mobile device, providing priori-tized rules that control which networkshould be chosen. Each rule specifies alocation and/or time for example, a cer-

tain Wi-Fi network can be valid when adevice is in a particular cell at a certaintime of day. The device will choose thenetwork with the highest priority.

Ericssons role in the standardizationwork currently being carried out by theWFA is to ensure that ANQP networkparameters, specified in Release 1, areincluded in Release-2 policies in sucha way that operators maintain controlover devices when they choose a net-work. Ericsson is also responsible forensuring that operator policies definedin Hotspot 2.0 are fully integrated into

3GPP Rel 12 policy.

Choosing the right RAT

The policy tools described so far arevaluable to the operator as they sup-port control over user experience andtake static or slowly changing networkparameters into account. However,they do not cater for the rapidly fluctu-ating RF environment experienced bya mobile device. To illustrate the point,when a mobile device moves into anarea covered by both Wi-Fi and 3G, itmay decide to switch to Wi-Fi, even

S2c

S2aPDN GW

ePDG

Trusted

WLAN access

Untrusted

WLAN access

S2c

Wi-Fi

SWu

(IPsec)

S2c

S2c

SWu

(IPsec)

S2c S2b

FIGURE 3 Interface architectureBO XB

Wi-Fi

handoverbehavior

Today

All handsets

switch to Wi-Fi

when it is

available.

Wanted

Possibility for

access selection

in operator

public hotspots,

depending on:

radio charac-teristics and

load situation;

subscription

parameters;

services;

other policies.

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though the coverage offered by the3G network is better.

Policies defined by ANDSF andHotspot 2.0 will help to overcome someof the problems associated with auto-matic handover to Wi-Fi networks.However, tracking of rapid changes inthe RF environment requires muchtighter integration of the Wi-Fi and cel-lular networks, and is not part of the

scope defined for Hotspot 2.0. To helpovercome this issue and include real-time RF-environment information toimprove the cellular/Wi-Fi decision-making process, Ericssons conceptfor heterogeneous-network solutionsmakes use of information from boththe cellular and Wi-Fi networks.

The concept supports integrationfor legacy devices as well as perfor-mance-enhancing features identifiedfor future device types. By using net-work load data from the cellular andWi-Fi network in the decision-making

process, for example, integrated Wi-Fisolutions can make informed real-timeRAT-selection decisions. The concept,for example, enables the network tocontrol Wi-Fi acceptance thresholds forlegacy devices. In the example illustrat-ed in Figure 2both Wi-Fi and 3G cov-erage are available. In such situations,devices will not be allowed to connectto the Wi-Fi network if signal strength

is below a given level a parameter thatcan be updated by the network in realtime.

To improve performance and conse-quently user experience even further,the long-term goal is to improve devic-es so they can receive instructions fromany access network to switch to a differ-ent network, and to spread informationacross networks about signal conditionand location.

Session mobility

Referring back to the use case, imagine

that our user is watching a streamingvideo over the cellular network whilewalking into the mall. When the device

switches from one network to another,the video should continue to play with-out any user intervention. To imple-ment this successfully, full IP-sessioncontinuity and IP-address preserva-tion between the cellular and the Wi-Finetwork are required.

I-WLAN, which determines howIP-interworking between cellular andnon-cellular networks takes place, hasbeen part of 3GPP specifications sinceRelease 67. This type of interwork-ing allows operators to integrate non-cellular access into the cellular packet

core network, providing harmonizedtraffic handling for cellular and Wi-Fiaccess. With packet core network inte-gration, operators gain improved visibil-ity and control over non-cellular trafficand consequently over the user expe-rience. Subscribers will be able to usetheir favorite services independent ofthe access network and without inter-ruption. As such, WLAN is an integralpart of mobile-broadband access and theinterworking enables subscribers to use

WLAN access and still be linked to oper-ator functions including charging, poli-

cy control, deep packet inspection (DPI),QoS and Lawful Interception (LI).

Session mobility between 3GPP (suchas UMTS and LTE) and non-3GPP (suchas WLAN) access networks was firstintroduced to 3GPP specifications inRelease 8, with continuous enhance-ments to this capability included in sub-sequent releases.

There are two ways to distinguishmobility in non-3GPP networks depending on whether the target net-work is trusted or not and whether themobility mechanisms used are network

based or client based.

Trusted or untrusted

Determining whether or not a Wi-Fi net-work is trusted in terms of 3GPP stan-dards depends largely on whether thesubscribers home operator trusts thesecurity of the WLAN deployment.The business relationship between theWLAN provider and the home opera-tor is often a factor in this equation. Forexample, when a subscriber connects toa WLAN provided by an operator otherthan their home operator, this WLAN

UE

Roaming scenarios

TWAN

1. Non-3GPPspecific procedures

2. Authentication and authorization

4. PCEF initiated IP-CAN sessionmodification procedure

2. EAPauthentication

0. GTP/PMIPv6tunnel

3. Create session request

5. Create session response

6. GTP tunnel

7. L3 attach

8. L3 attach completion

9. 3GPP EPS bearer release 9. 3GPP EPS bearer release

S-GWPDNGW

vPCRFAAAproxy hPCRF

HSS/AAA

FIGURE 4 S2a session mobility

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might be considered untrusted par-ticularly if the provider uses the publicinternet to connect to the home oper-

ator. In such a case, the specificationsallow the device to establish a securetunnel to an ePDG before the traffic isrouted to the core network of the oper-ator. In contrast, when subscribers con-nect to their operators own Wi-Fi, it isconsidered to be trusted and a securetunnel is not required.

Network- or client-based

Both network-based and client-basedmobility between 3GPP and WLAN (non-3GPP) networks are supported by 3GPPspecifications. The 3GPP to WLAN inter-

faces are S2a, S2b and S2c. The archi-tecture showing the three interfaces isillustrated inFigure 3. In all cases, ses-sion mobility is provided between the3GPP network and the WLAN networkwith the PDN GW acting as the user-plane anchor between the two.

S2a: The mobile device connectsto the Wi-Fi network using standardWLAN authentication procedures with-out any need for mobility or tunnelingsupport in the mobile device. PMIPv6or (as of Release 11) GTP protocols canbe used for the S2a interface between

the WLAN and the PDN GW, but GTP isalready widely deployed in mobile net-works and offers a range of performanceadvantages over PMIP. Either IPv4 orIPv6 may be used in the transport layer.

S2b:The wireless network is con-sidered an untrusted non-3GPP accessnetwork. The mobile device must estab-lish a secure IPsec/IKEv2 tunnel to anadditional network element, the ePDG,through which the PDN GW is thenaccessed. Either PMIPv6 or (as of Release10) GTP protocols can be used for theinterface between the ePDG and the

PDN GW, and either IPv4 or IPv6 trans-port may be used.

S2c:This option can be used overboth trusted and untrusted non-3GPPaccess networks. The mobile devicemust connect to the PDN GW usingDSMIPv6. In Release 10, the S2c optionadded support for IP mobility per flowin addition to IP session mobility. Thedrawback of this solution is that new cli-ents would be needed, whereas S2a canoperate in clientless mode compatiblewith todays devices.

For operator-deployed and fully

integrated Wi-Fi networks, the trust-ed WLAN model is most appropriate.In this case, the S2a interface is the

most cost-effective solution, allowingunmodified mobile devices to access thePDN GW via S2a.

Ericsson has held a leading role in theRelease 12 SaMOG project, which aimsto add full mobility across the S2a inter-face, including support from appro-priately enabled dual-mode devices. Atypical message sequence for sessionmobility is shown inFigure 4.

Conclusion

For most operators, Wi-Fi has become anintegral part of their mobile-broadband

strategy. Ericssons concept for hetero-geneous networks incorporates Wi-Fi,fully integrating it into mobile-accessand core networks.

The evolution of Wi-Fi technology through Hotspot 2.0, application ofoperator policy, intelligent RAT selec-tion and GTP session mobility willbring about a world where people nolonger know or care whether they areconnected using a cellular or Wi-Fi datanetwork, and operators will be able tocontrol the choice of connectivity tooptimize the user experience. Ericsson

has a leading role in standardizationefforts to ensure that the key elementsof Wi-Fi are implemented in 3GPP.

1. WBA and GSMA, March 2012, Press Release,

GSMA and WBA collaborate to simplify

Wi-Fi hotspot access for smartphones and

tablets, available at: http://www.wballiance.

com/2012/03/20/gsma-and-wba-

collaborate-to-simplify-wi--hotspot-access-for-

smartphones-and-tablets/

2. Wireless Broadband Alliance, Next GenerationHotspot Program, available at: http://

www.wballiance.com/wba-initiatives/

next-generation-hotspot/

3. Wi-Fi organization, 2012, White Paper, Wi-Fi

CERTIFIED Passpoint: A new program from the

Wi-Fi Alliance to enable seamless Wi-Fi access

in hotspots, available at: http://www.wi-.org/

register.php?le=wp_20120619

_Wi-Fi_CERTIFIED_Passpoint.pdf

4. Ericsson, June 2012, Trafc and Market Report,

available at: http://www.ericsson.com/res/

docs/2012/trafc_and_market

_report_june_2012.pdf

5. IEEE, 802.11u-2011 - IEEE Standard for

Information Technology-Telecommunications

and information exchange between

systems-Local and Metropolitan networks-

specic requirements-Part II, available

at: http://standards.ieee.org/ndstds/

standard/802.11u-2011.html

6. 3GPP, Technical Specication 24.234, 3GPPsystem to Wireless Local Area Network (WLAN)

interworking, available at: http://www.3gpp.org/

ftp/Specs/html-info/24234.htm

7. 3GPP, Technical Specication 24.312, 3GPP

Access Network Discovery and Selection

Function (ANDSF) Management Object (MO)

available at: http://www.3gpp.org/ftp/Specs/

html-info/24312.htm

8. 3GPP, Technical Specication 24.235, 3GPP

System to Wireless Local Area Network (WLAN)

interworking Management Object (MO), available

at: http://www.3gpp.org/ftp/Specs/html-

info/24235.htm

References

Stephen Rayment

is chief technology

ofcer for Wi-Fi productsat Ericsson. Previously, as

CTO of BelAir Networks,

he led the denition and delivery of the

industrys rst carrier Wi-Fi solutions.

He has over 30 years of product

experience in the telecommunications

industry and has been active in

industry standardization as an ofcer

in IEEE 802.11 and in the Wi-Fi Alliance.

Stephen is author of over 25 patents.

He holds a B.Sc. and an M.Sc. in

electrical engineering, from Queens

University in Kingston, Canada and a

diploma in administration, from the

University of Ottawa, Canada.

Joakim Bergstrm

is an expert in new radio-

access networks at

Design Unit Radio. He has

more than 10 years of

experience in standardization within

the 3GPP RAN area working with

HSPA, LTE and their evolution. He

holds an M.Sc. in electrical engineering

from the Royal Institute of Technology

(KTH), Stockholm. Within the radio

area, he has coordinated all ofEricssons standardization activities

and projects since 2011.

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achieving carrier-grade wi-fi in the 3gpp world

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