small cell interoperability in the ran

Small Cell Interoperability in the RAN Impossible Physics, Hard Design, or just Red-Tape?

V2.4, 1st October 2014

CTO N.D. Johnson

(C) 2014 ip.access Ltd All rights reserved

Small Cell Interoperability

Why do we care? • Some anecdotes from history • Abis, Iu-b, Iu-r

Beyond standards • NGMN, SCF and other interoperability initiatives

Buridan Telecom • In the end, you have to choose

The schizophrenic vendor • Can you be the incumbent and the upstart at the same time?

Interoperability and cloud-RAN • Don’t be beguiled into another layer of private interfaces

A message of hope • It might just work!


A traditional multi-vendor RAN deployment

3

A traditional multi-vendor RAN deployment divides the network into regions. A “traditional” residential femto deployment has no such regionality. Already we have a multi-vendor RAN, and it’s no niche.


A new generation of problems – inter-layer multi-vendor IOT for handover

4

Where multi-vendor IOT used to be a line across a country, now It’s possible at every handover


Laws-of-physics : Where are the issues?

Load balancing: • Reselection and Handover • both directions • 3G and LTE

Interference Management • Pilot/FACH power tuning • Avoidance and

coordination • Open and Closed mode

Synchronisation • Frequency synch • Time/frame synch

Solved? Relies On

Standard signalling R9 CSG + delta-SFN, MLB

CCO, ICIC, eICIC, CSG

PTP/NTP transport Off-channel NWL

…the physics is not impossible


Small Cell Forum Plugfests summary

Topics Taking Part

Test cases Venue

3G (1)

March 2010 IPSec,

Iuh interface 22 26 Sophia Antipolis, France

3G (2)

Jan 2011 HMS (TR-069) interface 14 35 Sophia Antipolis, France

3G (3)

June 2011 Mobility scenarios 12 42 Lannion, France

LTE (1)

June 2013 S1, X2, Mobility scenarios,

VoLTE 20 28 Kranj, Slovenia

LTE (2)

June/July 2014 Regression:

• S1, X2, Mobility, VoLTE, New

• HEMS, CMAS, CSFB, SON (ANR, PCI, MRO)

25 94 Paris, France

3G participation diminishes as the

problems disappear

LTE participation still growing as

the problems are addressed


But even here, the interoperability problems lurk

TR196 v2.0.1 is not backwards compatible with TR196 v.2.0.0 • WTF?

SCF and NGMN studies have shown key procedures in X2 are non-interoperable

X X

? ?

X


How has it come to be like this?

GSM A-bis interoperability: • Late 90s, attempts to interoperate vendor E BSC with vendor P BTS fail • Largely due to management model incompatibility

Early noughties, Radioframe succeeds in interoperating E// and NSN A-bis • 2009, Radioframe stops trading

ip.access tries to interoperate with 3rd party IP-BSCs • Just in time for the telecom winter • Pivots in 2001/2 to create a full RAN solution

2001, Kevab creates innovative node-B, with Iu-b to NSN and other RNCs • 2003, Andrew Corp acquire Kevab, then 3GNS acquire the tech in 2009, now?

The lesson is: • working to non-interoperable interfaces through incumbent proprietary

gateways is business suicide


The scale of the problem – how big are these interfaces?

0200400600800

1000120014001600

Abis+Gb Iu-b Iu-h LTE

Basestation to Controller pages of spec.

0

200

400

600

800

1000

1200

1400

GSM Iu-r Iu-rh X2

Cell to Cell pages of spec.

0

500

1000

1500

2000

2500

2G 3G 3G femto 4G

Radio Resource Control (RRC) Pages of spec.

050

100150200250300350400450500

2G 3G 3G femto 4G

RAN to Core pages of spec.

…the design is hard , but it is becoming more tractable


Buridan Universal Text and Telephony Company

awarded an operator’s license, but couldn’t decide

whether to build a single vendor RAN or multi-vendor

HetNet

?

The message? Commitment Matters

Multi-vendor: Multiple procurement, OAM and training overheads Take advantage of best-in-industry roadmaps Flexible to vendor corporate strategy and pricing Who’s the SI? Optimal network performance

Single vendor:

Simple procurement, operations/maintenance and

training

Tied to single roadmap

High cost to change

Vulnerable to vendor corporate strategy and pricing

Best effort network

performance


Schizophrenic vendors, they’re black and white

Vendors are ambivalent towards interoperability

“If we’re trying to displace an incumbent,

we’re all for it.”

Vendors are ambivalent towards interoperability

“ If we’re defending an incumbency, we move heaven and earth to question the value of it.”


Operator Process, and who’s the SI?

Operator processes are still largely tuned to macro deployment:

• Operator A: “it takes us six weeks to deploy a cell”

• Operator B: “each cell we deploy touches 17 departments in my organisation”

• AT&T (SCA 2013): “we can’t order equipment to be installed at a location that doesn’t have a street address – our tools won’t let us.”

Who fixes it when it’s broken

If it takes time to fix, then the customer will lose patience and revert to the

tried-and-tested ?


A message of hope…

Operator processes are still largely tuned to macro deployment, but are moving:

• Operator A: “it used to take us six weeks to deploy a cell. Now it takes us two hours”

• Operator B: “each cell we deploy used to touch 17 departments in my organisation. Now it’s two.”

• AT&T (SCA 2013): “we couldn’t order equipment to be installed at a location that doesn’t have a street address – our tools wouldn’t let us. But now we can.”

…the red tape was there, but with the right commitment, it’s now being cut



14

Small Cell Management

System

Small Cell Gateway

Public/Private Internet

EPC (LTE)

Backhaul Basestations Core Gateway

Small Cell layer

MSC/GSN (GSM+3G)

SecGW

Macro layer

Handset

RRC X2, Iu-r, SON

IPSec

Iu-h, TR69/196v2

Iu, S1

The interoperable interfaces are at least countable, and

based on standards


… but with a cloud-RAN on the horizon

15

Small Cell Management

System

Small Cell Gateway

Public/Private Internet

EPC (LTE)

Backhaul Radio heads Core Gateway

MSC/GSN (GSM+3G)

SecGW Macro and

small cell layer

handset

RRC

X2, Iu-r, SON

IPSec

Iu-h, TR69/196v2

Iu, S1

Fronthaul baseband

Security?

Transport , OAM incl.

SON?

Control and Data?

Cloud-RAN offers another opportunity to privatise the interfaces, and force operators towards a single-vendor RAN



• Operators are vocally insistent on multi-vendor interoperability on key interfaces • Incumbents will reluctantly agree to integrate in a multi-vendor context • The “who’s the SI?” question remains an issue

• the answer is rarely “the incumbent”, though it’s expensive for the incomer

• Initiatives such as the SCF Interoperability Plugfests are removing the sting and the risk from multi-vendor integration

• Technology such as Self-Organisation (centralised, distributed and hybrid) with standardised interfaces and procedures will also reduce the SI burden.

• With these issues in place… • Properly interoperable interfaces • Technology to reduce the SI burden • Exhaustive cross-industry laboratory pre-test • Operator commitment, with business processes to match

…we can do it!

It can be done..


Nick Johnson CTO, ip.access

Thanks for your attention…

[email protected]

mailto:[email protected]

small cell interoperability in the ran

Technology

multi vendor ran

multi vendor iot

rights reservedbut

rights reservedlaws

rights reservedhow

party ipbscsjust

vendor e bsc

rights reservedthe scale