TDMA TDMA f Slot1 Slot2 Slot3 t frame1

在TDMA系統中，如何做同步 • TDMA f Slot_1 Slot_2 Slot_3 t frame_1 frame_2 frame_3 • 一般TDMA系統 – Preamble內含有address以及同步資訊。 frame Preamble Information Message Tail bit

在TDMA系統中，如何做同步 • P 1901 • 1. All STAs within an access network shall be synchronized to a common clock. • 2. Each STA shall use its NTB_STA in generating the ATS (Arrival Timestamp). • 3. The ATS is the value of the NTB or NTB_STA when the first octet of the MSDU arrives at the MAC SAP of a station. • 4. It is used to provide jittercontrol and smoothing functions across the 1901 BSS.

在TDMA系統中，如何做同步 • head end (HE): Device that bridges an access cell to a backhaul network. There is one and only one active HE in a cell. Each active HE manages one cell, including all of the cell’s associated subcells. • The HE shall maintain a timer, called the NTB. The NTB is transmitted by the HE in the Beacon, and each STA in the access network synchronizes to the NTB. Cell HE_1 STA 2

在TDMA系統中，如何做同步 • 1. NTB(Network time base) — The BM shall maintain a timer, called the NTB. — The NTB is transmitted by the BM in the beacon. — Each STA in the BSS receiving the beacon synchronizes to the NTB. • 2. The Network Time Base may be used to： — Announce the expected beacon position and the Schedule within the beacon interval. — Derive the ATS and perform the jitter control function. • 3. NTB_STA — All stations in the BSS(Basic Service Set) shall maintain a local timer, called the NTB_STA. • 4. SAP(Service Access Point)

Omnet • Omnet模擬程式須包含以下資訊： • 1. NED(Network Description) language topology. . . in files with the. ned • 2. Message definitions……in files with. msg • 3. Simple module implementations and other C++ code (如802. 11 MAC、P 1901 MAC…等 )……in files with. cc

Omnet 此部份為NED language topology

Omnet • 目前進度： NED language topology已完成 目前尚在學習Message definition這部份. msg檔的建置。 • 之後進度： Message definitions……. 預計1週內完成 P 1901 MAC……. 預計1~1. 5個月完成