EE-290
V-0.4
Battery replacement SOP:
1. Remove the front cover
2. Slide out the 2pcs CR2450 batteries
3. Insert new 2pcs CR2450 batteries
4. Add the front cover.
8 Radio Specifications
Parameter
Min
Typ
Max
Unit
Remarks
Receiver sensitivity
-97
-89
dBm
Over the entire temp. and
operating voltage range
Nominal output power
-3
4.5
7
dBm
Frequency
2405
2480
MHz
Over the entire temp. and
operating voltage range
Transfer rate
250Kbit/s
RSSI range
100
dB
Signal strength indication
that can be reported to the
base station
8.1 Protocol
Modified 802.15.4 (Physical layer and Media Access Control layer).
8.1.1 The physical layer
The physical layer (PHY) provides the data transmission service, as well as the interface to the
physical layer management entity, which offers access to every layer management function and
maintains a database of information on related personal area networks. Thus, the PHY
manages the physical RF transceiver and performs channel selection and energy and signal
management functions. It operates on the above mentioned frequency band. The PHY layer is
100% compliant and is based on direct sequence spread spectrum (DSSS) technique with a
transfer rate of 250 kbit/s.
8.1.2 The medium access control layer
The medium access control (MAC) layer enables the transmission of MAC frames through the
use of the physical channel. Besides the data service, it offers a management interface and
itself manages access to the physical channel. It also controls frame validation, guarantees time
slots and handles node associations. Finally, it offers hook points for secure services. The EE-
202 does not make use of the optional network beaconing, instead it used a polling mechanism
to increase power efficiency. Some changes are made to the standard to allow for more
efficient data frames and better power efficiency, especially when nodes are not connected to a
base station.
8.2 Security
By default only the image transmission is encrypted using a proprietary encryption protocol.
Enhanced encryption/authentication can be requested on demand by loading different firmware
on the ESLs in combination with the loading of an encryption key and an additional ESL server
module. The protection method for RF-communication is done by 128-bit AES encryption.
10
