Scalability of bandwidth
Urban areas:
Most likely LTE will be deployed.
Stepwise deployment in UMTS 2.1 bands will be possible at a later stage.
Rural areas:
Option 1: deploy UMTS in 900 MHz band.
Advantage: rollout can start now
Disadvantage: a block of 5 MHz need to be taken out of the GSM band. Not a lot of operators can afford to take out this much of spectrum due to heavy usage in this band
Option 2: Introduce LTE in 900 MHz band
Advantage: reuse of GSM 900 Sites.
step by step introduction of LTE with smaller granularity (1.4 / 3 / 5 /MHz).
Cost per MByte decreases with introduction of new technologies.
From HSPA > LTE cost per MByte will reduce with more than 70%
Why?
-Increased spectral efficiency > bits per Hz per cell for LTE (2X2 MIMO) ~ 1.7
-Flat architecture.
-Reuse of spectrum > Refarming of existing 900 MHz band in rural areas possible. For urban larger bandwidth expected in 2.6 GHz
SAE: System Architecture Evolution
SAE GW: Serving Gateway +PDN Gateway
UDP: User Datagram Protocol ( L4 Transport Layer)
SCTP: Stream Control Transmission Protocol. For IP signalling
GTP: GPRS Tunnelling Protocol ( same as for UMTS Rel 99): user plane traffic