xN930 M.2 Hardware User Guide
3.6
In-Device Coexistence Interface
As more and more radios are added to PC Ultrabook™ and tablet platforms, the sources RF
interference increases significantly as multiple radios will have overlapping transmissions
and receptions. This problem will increase further as overlapping bands continue to be rolled
out; WIFI, BT, WWAN will all use overlapping band from 2300 MHz to 2600 MHz.
In-Device Coexistence is a feature which improves the user experience and maximizes
throughput and Quality of Service of connectivity systems (WLAN, BT and GNSS) when
these radios are simultaneously running with the WWAN M.2 LTE modem.
A diagram of the In-Device Coexistence architecture is shown in Figure 6.
Application
Processor
apps
coexistence
interface
Connectivity Chip
(WLAN/BT/GNSS)
NRT
Coexistence
interface
RT
Coexistence
interface
X-GOLD™ 716
apps
coexistence
interface
NRT
Coexistence
interface
RT
Coexistence
interface
CPU
NRT
coexistence
controller
LTE L1
RT
coexistence
controller
Message –based I/F)
IDC_CwsPriority
NRT Apps Coex I/F
Message –based I/F)
NRT Coex I/F
IDC_LteFrameSync
IDC_LteDtxEnv
Figure 9 In-Device Coexistence Architecture
Seamless Co-running
In-Device-Coexistence primarily aims at avoiding interference between radio systems to
allow seamless co-running where LTE and WLAN/BT/GNSS ensuring their maximum
throughput and performance. To do so, a Non Real Time (NRT) coexistence controller is
implemented on the ARM™ CPU. The NRT coexistence controller centralizes LTE, WLAN,
BT and GNSS information and performs interference avoidance mechanisms, selecting
interference-safe frequency configurations whenever possible. The NRT coexistence
controller is also in charge of enabling some Real Time (RT) coexistence mechanisms when
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