Comnets GPRS Protocol Stack (Source: Fig

Four Generations of Digital Mobile Radio Networks - From 2G to 5G Systems -

Bernhard Walke

Communication Networks (ComNets) Research Group RWTH Aachen University, Germany ------

Oct. 23, 2015

ComNets Content

1. Mobile Radio Networks and Services

2. Frequency Spectrum, Radio Propagation

3. Transmission Technology

4. Techniques for Increasing Capacity

5. Future (5G) Mobile Systems Architecture

6. Summary

ComNets 2 Growth of transmitted Data world-wide - Mobile Video is the main application -

Cumulated Annual Growth CAGR

Exa = 10 exp 16

Figures in parentheses refer to 2014, 2019 traffic share. Source: Cisco VNI Mobile, 2015

ComNets World-wide Standardized Digital Mobile Radio Systems

Mobile System: 1989: GSM (Global System for Mobile) – 2G -- 200 kHz channel width, 15 kbps 2001: GPRS (General Packet Radio Service) in GSM – 2G - 64 kbps 2004: EDGE (Enhanced Data Rate for GSM Evolution) – 2.5G – 256 kbps

2003: UMTS (Universal Mobile Telecom. System) – 3G – 2 MHz – 1 Mbps 2006: HSPA+ (High Speed Packet Access) – 3.5G – 2 MHz channel width, 15 Mbps

2009: LTE (Long Term Evolution) – 4G – 20 MHz channel width – 100 Mbps 2014: LTE-A (Long Term Evolution – Advanced) – 4.5G – n x 20 MHz – 1 Gbps

2020: 5G (Self-Organizing Mobile Network for Internet of Things)–10 Gbps

Wireless Systems: 1999: WLAN (Wireless Local Area Network) – 1, 2, 5 MHz - < 200m, 20-1.000 Mbps 2000: DECT (Digital European Cordless Telecommunications) – 2 MHz – 50m 2003: Bluetooth – 1, 2 MHz – 10m

ComNets 4 Mobile Radio Network Architecture (Example UMTS)

Andere Mobil- funknetze

Öffentl. Telefon- netz/ISDN USIM Datennetze/ Internet

USIM MS RAN CN

Core Transport functions, mobility management, Subscriber data

Network base, service control, etc.

Radio Access Radio technology specific fixed network functions Network (Radio Resource Management, etc.)

• Radio Interface (Radio transmission) Mobile Station • Service control and user interface.

UMTS Subscriber Identity Module • Contains subscriber specific data • Enables authentified access to the mobile network.

Important interfaces between function blocks

Source: J. Zander, P. Mähönen: Riding the Data Tsunami in the Cloud: Myths and Challenges in Future Wireless Access, IEEE Communications Magazine, March 2013, 145-151 ComNets Content

1. Mobile Radio Networks and Services

2. Frequency Spectrum, Radio Propagation

3. Transmission Technology

4. Techniques for Increasing Capacity

5. Future (5G) Mobile Systems Architecture

6. Summary

ComNets 7 Betriebsfrequenzen von 2G - 4G Mobilfunksystemen

The radio interface of mobile terminals must be a standard to enable world wide usability.

Four frequency bands are defined for mobile use by ITU-R:

For large cells: - 450-470 MHz - 790-806 MHz

For small cells: - 2300-2400 MHz - 3400-3500 MHz

In some regions there is more spectrum available.

New assignments for 5G will only happen at WRC2019

Spectrum preferred by NGMN a. 6 – 20 GHz (e.g. 5.9 - 8.5 GHz, 9.9 - 10.6 GHz) b. 20 GHz – 30 GHz (e.g. 21 - 23.6 GHz, 24.5 - 29.5 GHz, c. 30 – 86 GHz (e.g. 31.8 - 33.4 GHz, 40 - 43.5 GHz, 66-76 GHz, 81-86 GHz,

n Receive signal strength follows a 3rd to 4th Increased Increased exponent law of distance transmit power carrier frequency Cell border between sender and pico cell receiver.

n The receiver needs a [dB] Minimum required minimum signal threshold receive level to be able to decode loss incoming signals. Cell border Micro cell n Higher transmit power Path increases cell radius.

n Path loss increases with 40 60 80 100 120 140 160 higher carrier frequency. 0 200 400 600 800 1000 Distance [m] Antennenstandort der Basisstation

Je größer der Datenverkehr / qm, desto kleiner muss die Zelle sein. Bei gegebener Frequenzausstattung hängt die Datenkapazität der Zelle nicht vom Zellradius ab. Je größer der Zellradius, desto kleiner die Datenkapazität / qm.

Pico Zelle: Stadtzentrum: 100 m Radius. Macro Zelle: Stadtrand, 0,5 - 5 km Radius

An Orten mit hohem Datenverkehr versorgt eine Basisstation drei Zellen: Drei-Sektorzelle.

SINR = Signal to Interference and Noise Ratio. Example: Base station with three sectors (3 cells)

Interference is highest at cell border (blue areas), where data rate is lowest.

ComNets Areal Radio Coverage by Pico versus Macro Cells

Signal level above red circle area only Pico Cells appears in Macro Cells Macro Cells

(a) (b)

Downlink Interference (dBm) für typical real systems (a) Pico-Cells in Manhattan Grid (Cell Radius is 100m) Walfish-Ikegami path loss model; Transmit power: 30dBm (1W). (b) UMTS: Macro Cells (Cell radius is 500m); Okumura-Hata path loss model; Transmit power: 40dBm (10W). Pico Cell Networks in mm-Wave Frequencies are possible Content

1. Mobile Radio Networks and Services

2. Frequency Spectrum, Radio Propagation

3. Transmission Technology

4. Techniques for Increasing Capacity

5. Future (5G) Mobile Systems Architecture

6. Summary

ComNets 15 Circuit switching (TDMA) in GSM

• A periodic frame with 8 time slots (0..7) is transmitted on a GSM frequenc channel • Each periodic time slot is a circuit switched physical TDMA channel. • A time slot carries a Normal Burst or a signaling burst. 4.615 ms

TDMA Frame Frequency/MHz 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7

960 time slot training Downlink, DL data bits data bits Normal Burst ... 935 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 57 bit 26 57 bit Duplex distance Gap between uplink and downlink 3 tail bits 1 toggle bit 3 tail bits 915 burst (148 bit) Uplink, UL time slot (156.25 bit)

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 ... 0.577 ms 890

Time/ms ComNets Packet switching for Data Transmission

Packet switching: The Data stream of the information source is segmented into Packets. Packets contain address of Sender and Receiver and user data. Ps are routed via radio and core network / Internet to the destination. Destination re-assembles the original information from the packets received. ------Packet switching introduced 2001 as General Packet Radio Service (GPRS)* in GSM mobile radio network. Until 2001 GSM only supported channel switching.

In GPRS packets of different mobile stations are multiplexted to a circuit-switched mobile TDMA channel to be transmitted via GSM. GPRS as the first made Internet mobile - worldwide. * B. Walke et. al.:CELLPAC - A Packet Radio Protocol Applied to the Cellular GSM Mobile Radio Network. Proc. 41th IEEE Vehicular Technology Conference, St. Louis, Missouri, USA, 05/1991, 408-413

ComNets GPRS Protocol Stack (Source: Fig. 4, B. Walke: Mobile Radio Networks 2002)

Same functions in protocol stacks of adjacent systems

4 TCP/UDP communicate logically (horizontally) with each other. TCP/UDP Data flow is vertically in protocol stacks. CO end-to-end L3 virtual connecon 3 IP / X.25 IP / X.25 CL IP

SNDCP GTP SNDP GTP

UDP/TCP LLC DLCI CO / CL LLC UDP/TCP UDP/TCP 2

RLC / MAC IP IP RLC Connecon RLC BSSGP BSSGP IP TBF CO Network Network MAC MAC L2 L2 L2 Service Service

1 Radio Channel L1 bis L1 L1 GSM RF GSM RF L1 bis L1 Phy Wire Wire MS BSS SGSN GGSN DTE

Um Gb Gn Um = Radio interface Gb, Gn = Interfaces between core network elements

TBF = Temporary Block Flow MS = Mobile Station SGSN/GGSN = Router CO / CL = Connection oriented / C-less BSS= Base Station Subsystem DTE= Data Terminal at fixed network ComNets GPRS Logical Channels

Group Channel Name Direction Function PCCCH PRACH Packet Random Access Channel UL random access PPCH Packet Paging Channel DL paging PAGCH Packet Access Grant Channel DL access grant PNCH Packet Notification Channel DL multicast PBCCH PBCCH Packet Broadcast Control Channel DL broadcast PTCH PDTCH Packet Data Traffic Channel UL/DL data PACCH Packet Associated Control Channel UL/DL assoc. Control

ComNets 4G LTE System is a packet switched network with a 10ms-Periodic MAC Frame*

Time Radio Frame (10 ms) Freq. Freq. Freq.

bit Semi-Persistent Scheduling (SPS) bit bit bit 344 344 344 344

bit Source: Maciej Mühleisen 2015 bit 344 (SID) bit 344 bit bit 44 344 1 344

Control 20 ms Channels Subframe (1 ms) (CCHs) 100 bit Number of Header 244 bit PRBs depends on OFDMA Resource CCH describes Element channel resource 344 bit quality 12 Subcarriers 1212 Subcarriers Subcarriers assignment (SINR) in PDCCHs Physical * B. Walke et.al.: „Wireless ATM:One Air-Interface Transport and BlockNetwork (TB) at receiver Resource Slot Protocols of the Mobile Broadband System“, IEEE Personal Block (PRB) (1 or more PRBs) Communications Magazine, August 1996, 50-56. Pair PDCCH: Physical Downlink Control Channel; SINR: Signal to Interference and Noise Ratio Maciej Mühleisen, ComNets 20/14 Content

1. Mobile Radio Networks and Services

2. Frequency Spectrum, Radio Propagation

3. Transmission Technology

4. Techniques for Increasing Capacity

5. Future (5G) Mobile Systems Architecture

6. Summary

ComNets 21 Cell Capacity vs. Distance is Inverse to the Needs

Radio range of base station limited by • Pathloss & signal shadowing • Max. permitted transmit power. Actual Available Capaci ty vs. Requested Capac ity t

è The more distant a terminal is from n e / y m the base station, the smaller is the t i Needs: e c l

available capacity/m2 p Number of UTs E

a In distance d C e r

è The higher the radio frequency A Available the larger the pathloss is: Cell borde r è # of base stations required increases Dramatically with frequency (CAPEX / OPEX) 22012005 Requested by use rs

è Most user terminals are far away from the base station (close to cell border) 22016010

Location of Distance d è Interfercence by neighbor stations is highest at cell border. the Base Station

UT = User Terminal; CAPEX = Capital Expenditure; OPEX = Operational Expenditure;

ComNets 22 Scattering of mm-Waves under beam antenna

B ut to n

High angle of incidence due to multiple reflections fall outside of Rx Tx reflections are beamwidth relatively short due to narrow Tx beamwdith

DL transmission reflections only result from obstacles located in the antenna beam. UL reflections by obstacles outside the beam miss the receiver

ComNets Smart Antenna for Space Division Multiple Access, SDMA

• Base Station uses antenna array to form beams (with side lobes)

• A signal is directed to user 1 and a Zero of antenna diagram is steered to user 2 (line diagram)

• At the same time another signal is directed to user 2 and a Zero is steered to user 1 (dashed diagr.)

• Multiple spatially separated user terminals are served in parallel

Signal Amplitudenstärke eines beam forming Algorithmus mit zwei UTs

ComNets 24 Data Rate under Multiple Input Multiple Output (MIMO) Signal Transmission

Sector Cell Beam Forming (BF) Coordinated Beam Forming (CBF) [bit/s/Hz] Data Rate Rate Data • Without beam forming (left: Sector cell) the pocket lamp effect is clearly visible

• Beam forming (middle) substantially increases data rate in whole cell sector.

• Co-ordinated beam forming requires co-operation of neighbored base stations. Data rate further increases.

Benedikt Wolz, ComNets 25/12 Relay based multi-hop communication with self-backhauling of eNBs Example: Strong shadowing

Channel Group 1 Channel Group 2

1. 2. 3.

Source: Line of Sight ComNets 2003

Communication Networks, Aachen University (RWTH) 26 Optimally Placed Relays for Homogeneous Radio Coverage

K. Sambale, B. Walke: „DF-Relay positioning for maximum cell capacity“. 18th European Wireless Conference , Poznan, Poland, April 2012, 1-6. Cell Small Cells Cell

Radio Cells without Relays. Three optimally placed Relays per Sector (the area is served more homogeneous) Relays cells are Small Cells ComNets Content

1. Mobile Radio Networks and Services

2. Frequency Spectrum, Radio Propagation

3. Transmission Technology

4. Techniques for Increasing Capacity

5. Future (5G) Mobile Systems Architectures

6. Summary

ComNets 28 Mobile Internet and Internet of Things are major driving forces for 5G.

In 2020: 1000 times greater capacity to connect 100B devices.

5G capabilities as defined by key performance target values:

Peak data rate ≥ 10Gbps, Minimum guaranteed user data rate ≥ 100Mbps, Connection density ≥ 1M connections/ km2, Tra ffic density ≥ 10 Tbps/ km2,

Radio latency ≤ 1 ms, E2E latency ≤ 10 ms for immersive and tactile user experience,

Mobility up to 500 km/h

To achieve this, higher efficiency is required, namely 5~15 times spectral, 100+ times energy, and 100+ times cost efficiency.

ComNets „More Spectrum“ increases 5G Capacity much more than „Cell Densiﬁcaon“

ComNets WLAN Mesh Network compeng to 4G System with WLAN oﬀ-loading

Quelle: D. Castor (InterDigital): 5G mm-Wave, PIMRC, Sept. 2014 ComNets Mm-Wave supported 5 G System

Massive MIMO transmission Heterogenes Mobilfunknetz aus 3GPP-System und mm-Wellen basiertem Mobilfunk für Hotspots basierend auf drei Technologien: Bleis-Beamforming, Vermaschung von Zugangspunkten (backhauling of BSs) und mobile Funkschnistelle. Quelle: D. Castor (InterDigital): 5G mm-Wave, PIMRC, Sept. 2014 ComNets Ultra-dense Network mit self-backhauling and dynamic pencil beam control

R. Baldemair, T. Irnich et.al.: Ultra-Dense Networks in mm-Wave Frequencies, IEEE Communicaons Magazine, Jan. 2015, 202-208 ComNets Beam steering of mm-Wave based Mobile Radio and Multi-hop first Proposed in 1985

B. Walke, R. Briechle: A local cellular radio network for digital voice and data transmission at 60GHz, Proc. Cellular & Mobile Communications International, London, Nov. 1985, 215-225

Benedikt Wolz, ComNets 34/12 Digital Mobile Radio Systems

• Since 1989 available world-wide with standard radio interfaces. • Every 10 years: - New generation of radio interface. - Improvement of user data rate by factor 10. • Wireless and mobile radio dominate Internet Access: 6 Billion mobile terminals* but only 800 Million fixed Internet terminals.

Key concepts originate from ComNets, RWTH Aachen, e.g.: • Packet switching (GPRS ,1991**): mobile Internet access in 2G/3G/4G • MAC-frame for radio resource management of LTE/WiMAX systems (1995) • Multi-hop Relay 1999: better radio coverage / larger radio reach • Small Cells for cell capacity improvement (2004). • Dynamic Beamsteering in self-organizing Multi-hop Networks*** (1985) • IEEE 802.11s (Mesh) und 802.11e (QoS Unterstützung) (2002-06). * gsa.com; ** B. Walke: The Roots of GPRS - The first System for Mobile Packet based Global Internet Access. IEEE Wireless Communications, October 2013, 2-23. *** B. Walke, R. Briechle: A local cellular radio network for digital voice and data transmission at 60GHz, Proc. Cellular & Mobile Communications International, London, Nov. 1985, 215-225 ComNets

Danke für Ihre Aufmerksamkeit!

Thank you for your time!

ComNets FFV-Workshop Bremen Panel Slide (B. Walke)

• Mobile communication enables a steady growth of new applications (“APPs”);

• A revolution of processes is expected for • Humans through sensor / actuator networks • Production / automation (Industrie 4.0), • Healthcare / Judiciary system (law), • Public service /administration, logistics, public traffic, etc.

• Mobile radio for everybody (GSM) exists since only 25 years • Since 10 years we have mobile Internet access (GPRS / UMTS / LTE.) à Internet became omni-present 10 years ago. • Internet is unsafe like the operating systems of computers connected • Internet eases world-wide security attacks and non-prosecuted criminal actions • All this will dramatically change culture and living style - more then TV did (1960) • Are we prepared for this – who is taking responsibility for this development?

ComNets