@PCrepieux #Devoxx Energy, latency: I love you, me neither Pierre Crepieux Orange 

@PCrepieux #Devoxx Power consideration • A transmitter has to be constantly listening • Transmitting a signal over a distance requires power • For a wired network, this relationship is linear • For a wireless network, it follows an inverse square law source: https://en.wikipedia.org/wiki/Inverse-square_law 

@PCrepieux #Devoxx Power consideration • The more users on a base station → the more noise on the air interface. • The more noise on the air interface → the higher the power has to be. • The faster the data is sent → the more power is needed • Modem might require around 2 Watts • 8Wh (battery capacity) gets empty within a couple of hours 

@PCrepieux #Devoxx DRX Discontinuous Reception 

@PCrepieux #Devoxx Network architecture RNC GGSN MSC SGSN NodeB Iub Iu PS Gn HLR GMSC 

@PCrepieux #Devoxx Application Architecture Webservice ViewModel Remote data source LiveData LiveData Activity repo model SQLite 

@PCrepieux #Devoxx UMTS RNC GGSN MSC SGSN NodeB Iub Iu PS Gn HLR GMSC Radio Bearer Iu Bearer Gn bearer PDP context external bearer End to end connection Radio Access Bearer 

@PCrepieux #Devoxx I-DRX (DRX while Idle) • A smartphone have to listen to a couple of physical channels depending on its state • To reduce energy consumption, smartphones turns off the radio as much as possible • Incoming traffic, is notified through the Paging Channel • A smartphone usually listens the paging channel every ~1s P a g i n g t (s) 

@PCrepieux #Devoxx 

@PCrepieux #Devoxx RRC (Radio Resource Control) • RRC covers multiple concepts: • function implemented in the RNC (Radio Network Controller) • a connection between the user equipment and the RRC function • a Control Plane protocol • a state machine • RRC goals: • establishment/configuration of radio bearers • paging/notification • Control of QoS • … 

@PCrepieux #Devoxx UMTS RRC Cell_DCH Cell_FACH Cell_PCH URA_PCH IDLE Not Connected Connected 

@PCrepieux #Devoxx UMTS RRC Cell_DCH Cell_FACH Cell_PCH URA_PCH IDLE Not Connected Connected 

@PCrepieux #Devoxx UMTS RRC Cell_DCH Cell_FACH Cell_PCH URA_PCH IDLE Not Connected Connected 2s 0,5s 

@PCrepieux #Devoxx UMTS RRC Cell_DCH Cell_FACH Cell_PCH URA_PCH IDLE Not Connected Connected 2s 0,5s 

@PCrepieux #Devoxx Tailing periods tailing period: 5s tailing period: 10s tailing period: 10s or more RRC connected RRC not connected tail DCH tail FACH 10 45 3 30 6 15 

@PCrepieux #Devoxx cDRX Connected DRX 

@PCrepieux #Devoxx LTE RNC P-GW eNodeB GGSN MSC SGSN HLR GMSC S-GW MME HSS 

@PCrepieux #Devoxx LTE RNC P-GW eNodeB GGSN MSC SGSN HLR GMSC S-GW MME HSS Radio Bearer S1 Bearer S5/S8 Bearer EPS Bearer End to end connection E-RAB external bearer 

@PCrepieux #Devoxx LTE RRC Continuous RX short DRX long DRX IDLE RRC_Idle RRC_Connected 0,1 - 0,2s 

@PCrepieux #Devoxx cDRX (Connected DRX) QCI cont. rx(ms) on time(ms) short DRX(ms) long DRX(ms) back to idle(s) 9 200 10 20 320 15 9 100 10 80 200 10 9 200 4 X 80 30 9 always on X X X 5 1 10 4 X 40 30 0 1 0 1 1 0 0 0 1 on time on time short DRX cycle long DRX cycle continuous RX short DRX long DRX 

@PCrepieux #Devoxx eDRX Extended DRX 

@PCrepieux #Devoxx eDRX 0 1 0 1 1 0 0 0 1 paging window eDRX cycle (n x HyperFrames) t (ms) t (s) C-eDRX: • Extended DRX cycles up to 10.24 s (cDRX limit was 2,56s) I-eDRX: • Extended DRX cycles jusque ~44min for LTE-M (~3hr for NB-IOT) 

@PCrepieux #Devoxx PSM (Power Saving Mode) 0 1 0 1 1 0 0 0 0 •Pretty much like shutting down the radio for real, but the device remains attached to the network •PSM cycle length up to 400 days ! •10 years battery life … PSM cycle 

@PCrepieux #Devoxx PSM (on Wifi) • As opposed to CAM (Constant Awake Mode) • Transmission power of Wi-Fi is much lower than mobile (Local area vs Wide area) • Energy consumption is still pretty high (especially with 802.11n) b e a c o n TIM 100ms PSM cycle Polls data from the AP 

@PCrepieux #Devoxx 5G AMF UPF SMF UPF gNB UDM 

@PCrepieux #Devoxx 5G RRC RRC Connected RRC Inactive Disconnected/ IDLE Not Connected Connected 

@PCrepieux #Devoxx 

@PCrepieux #Devoxx Thanks