diff --git a/.github/workflows/simulation-1.2.yml b/.github/workflows/simulation-1.2.yml
index d0d5fc4fc..06eb8c152 100644
--- a/.github/workflows/simulation-1.2.yml
+++ b/.github/workflows/simulation-1.2.yml
@@ -98,3 +98,29 @@ jobs:
     - name: Codecov
       run: |
         bash <(curl -s https://codecov.io/bash) -x "${{ matrix.compiler.gcov }}" -Z
+
+  expects:
+    runs-on: ubuntu-18.04
+    env:
+      COVERAGE: 1
+      THREAD_VERSION: 1.2
+      VIRTUAL_TIME: 0
+    steps:
+    - uses: actions/checkout@v2
+    - name: Bootstrap
+      run: |
+        sudo apt-get --no-install-recommends install -y expect ninja-build
+    - name: Run RCP Mode
+      run: |
+        OT_OPTIONS=-DOT_READLINE=OFF NODE_MODE=rcp ./script/test build expect
+    - name: Keep-1-2-only
+      run: |
+        ./script/test tar posix 1.2-bbr
+        ./script/test tar simulation 1.2-bbr
+    - name: Keep POSIX Only
+      run: |
+        ./script/test tar simulation 1.2
+    - name: Codecov
+      uses: codecov/codecov-action@v1
+      with:
+        fail_ci_if_error: true
diff --git a/examples/platforms/nrf528xx/nrf52811/openthread-core-nrf52811-config.h b/examples/platforms/nrf528xx/nrf52811/openthread-core-nrf52811-config.h
index 47854e8a1..c4cfa9a24 100644
--- a/examples/platforms/nrf528xx/nrf52811/openthread-core-nrf52811-config.h
+++ b/examples/platforms/nrf528xx/nrf52811/openthread-core-nrf52811-config.h
@@ -150,6 +150,16 @@
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_PLATFORM_USEC_TIMER_ENABLE
  *
diff --git a/examples/platforms/nrf528xx/nrf52833/openthread-core-nrf52833-config.h b/examples/platforms/nrf528xx/nrf52833/openthread-core-nrf52833-config.h
index d61579d0b..e037cd9d0 100644
--- a/examples/platforms/nrf528xx/nrf52833/openthread-core-nrf52833-config.h
+++ b/examples/platforms/nrf528xx/nrf52833/openthread-core-nrf52833-config.h
@@ -172,6 +172,16 @@
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_PLATFORM_USEC_TIMER_ENABLE
  *
diff --git a/examples/platforms/nrf528xx/nrf52840/openthread-core-nrf52840-config.h b/examples/platforms/nrf528xx/nrf52840/openthread-core-nrf52840-config.h
index a312d84bb..23c10ac95 100644
--- a/examples/platforms/nrf528xx/nrf52840/openthread-core-nrf52840-config.h
+++ b/examples/platforms/nrf528xx/nrf52840/openthread-core-nrf52840-config.h
@@ -172,6 +172,16 @@
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_PLATFORM_USEC_TIMER_ENABLE
  *
diff --git a/examples/platforms/simulation/openthread-core-simulation-config.h b/examples/platforms/simulation/openthread-core-simulation-config.h
index e8c0c6fbb..89def7712 100644
--- a/examples/platforms/simulation/openthread-core-simulation-config.h
+++ b/examples/platforms/simulation/openthread-core-simulation-config.h
@@ -117,6 +117,16 @@
 #ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
 #endif
+
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2)
+#endif
 #endif // OPENTHREAD_RADIO
 
 /**
diff --git a/include/openthread/platform/radio.h b/include/openthread/platform/radio.h
index 7b0c039a3..c5d5b39b2 100644
--- a/include/openthread/platform/radio.h
+++ b/include/openthread/platform/radio.h
@@ -125,6 +125,7 @@ enum
     OT_RADIO_CAPS_CSMA_BACKOFF     = 1 << 3, ///< Radio supports CSMA backoff for frame transmission (but no retry).
     OT_RADIO_CAPS_SLEEP_TO_TX      = 1 << 4, ///< Radio supports direct transition from sleep to TX with CSMA.
     OT_RADIO_CAPS_TRANSMIT_SEC     = 1 << 5, ///< Radio supports tx security.
+    OT_RADIO_CAPS_TRANSMIT_TIMING  = 1 << 6, ///< Radio supports tx at specific time.
 };
 
 #define OT_PANID_BROADCAST 0xffff ///< IEEE 802.15.4 Broadcast PAN ID
@@ -516,6 +517,17 @@ void otPlatRadioSetMacFrameCounter(otInstance *aInstance, uint32_t aMacFrameCoun
  */
 uint64_t otPlatRadioGetNow(otInstance *aInstance);
 
+/**
+ * Get the bus speed in bits/second between the host and the radio chip.
+ *
+ * @param[in]   aInstance    A pointer to an OpenThread instance.
+ *
+ * @returns The bus speed in bits/second between the host and the radio chip.
+ *          Return 0 when the MAC and above layer and Radio layer resides on the same chip.
+ *
+ */
+uint32_t otPlatRadioGetBusSpeed(otInstance *aInstance);
+
 /**
  * @}
  *
diff --git a/script/test b/script/test
index 050770bd7..ae8e5a1d7 100755
--- a/script/test
+++ b/script/test
@@ -233,12 +233,16 @@ do_expect()
 {
     local ot_command
     local rcp_command=
+    local mtd_command=
     local test_patterns
 
     if [[ ${NODE_MODE} == rcp ]]; then
         ot_command="${OT_CLI_PATH}"
         rcp_command="${RADIO_DEVICE}"
-        if [[ ${OT_NATIVE_IP} == 1 ]]; then
+        if [[ ${THREAD_VERSION} == "1.2" ]]; then
+            mtd_command="${OT_BUILDDIR}/cmake/openthread-simulation-${THREAD_VERSION}/examples/apps/cli/ot-cli-mtd"
+            test_patterns=(-name 'v1_2-*.exp')
+        elif [[ ${OT_NATIVE_IP} == 1 ]]; then
             test_patterns=(-name 'tun-*.exp')
         else
             test_patterns=(-name 'posix-*.exp' -o -name 'cli-*.exp')
@@ -254,9 +258,9 @@ do_expect()
         mkdir tmp
         {
             if [[ ${OT_NATIVE_IP} == 1 ]]; then
-                OT_COMMAND="${ot_command}" RCP_COMMAND="${rcp_command}" sudo -E expect -df "${script}" 2>"${log_file}"
+                OT_COMMAND="${ot_command}" RCP_COMMAND="${rcp_command}" MTD_COMMAND="${mtd_command}" sudo -E expect -df "${script}" 2>"${log_file}"
             else
-                OT_COMMAND="${ot_command}" RCP_COMMAND="${rcp_command}" expect -df "${script}" 2>"${log_file}"
+                OT_COMMAND="${ot_command}" RCP_COMMAND="${rcp_command}" MTD_COMMAND="${mtd_command}" expect -df "${script}" 2>"${log_file}"
             fi
         } || {
             local exit_code=$?
diff --git a/src/core/config/mac.h b/src/core/config/mac.h
index 6f4be094e..0aeb921b3 100644
--- a/src/core/config/mac.h
+++ b/src/core/config/mac.h
@@ -139,6 +139,16 @@
 #define OPENTHREAD_CONFIG_MAC_MAX_TX_ATTEMPTS_INDIRECT_POLLS 4
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_MAC_CSL_REQUEST_AHEAD_US
+ *
+ * Define how many microseconds ahead should MAC deliver CSL frame to SubMac.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_CSL_REQUEST_AHEAD_US
+#define OPENTHREAD_CONFIG_MAC_CSL_REQUEST_AHEAD_US 2000
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_MAC_FILTER_ENABLE
  *
@@ -295,6 +305,16 @@
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE 0
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE 0
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_ENERGY_SCAN_ENABLE
  *
@@ -312,7 +332,7 @@
  *
  */
 #define OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE \
-    (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2) && OPENTHREAD_FTD
+    (OPENTHREAD_CONFIG_THREAD_VERSION >= OT_THREAD_VERSION_1_2) && (OPENTHREAD_FTD || OPENTHREAD_RADIO)
 
 /**
  * @def OPENTHREAD_CONFIG_MAC_CSL_RECEIVER_ENABLE
diff --git a/src/core/config/openthread-core-config-check.h b/src/core/config/openthread-core-config-check.h
index 788c10edc..5b537aaaf 100644
--- a/src/core/config/openthread-core-config-check.h
+++ b/src/core/config/openthread-core-config-check.h
@@ -506,8 +506,8 @@
 #if (OPENTHREAD_CONFIG_THREAD_VERSION < OT_THREAD_VERSION_1_2)
 #error "Thread 1.2 or higher version is required for OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE"
 #endif
-#if (!OPENTHREAD_FTD)
-#error "FTD is required for OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE"
+#if (!OPENTHREAD_FTD && !OPENTHREAD_RADIO)
+#error "FTD or RADIO is required for OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE"
 #endif
 #endif // OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
 
diff --git a/src/core/mac/sub_mac.cpp b/src/core/mac/sub_mac.cpp
index 03d04c45e..790426cc8 100644
--- a/src/core/mac/sub_mac.cpp
+++ b/src/core/mac/sub_mac.cpp
@@ -105,9 +105,13 @@ otRadioCaps SubMac::GetCaps(void) const
     caps |= OT_RADIO_CAPS_TRANSMIT_SEC;
 #endif
 
+#if OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+    caps |= OT_RADIO_CAPS_TRANSMIT_TIMING;
+#endif
+
 #else
     caps = OT_RADIO_CAPS_ACK_TIMEOUT | OT_RADIO_CAPS_CSMA_BACKOFF | OT_RADIO_CAPS_TRANSMIT_RETRIES |
-           OT_RADIO_CAPS_ENERGY_SCAN | OT_RADIO_CAPS_TRANSMIT_SEC;
+           OT_RADIO_CAPS_ENERGY_SCAN | OT_RADIO_CAPS_TRANSMIT_SEC | OT_RADIO_CAPS_TRANSMIT_TIMING;
 #endif
 
     return caps;
@@ -341,18 +345,26 @@ void SubMac::StartCsmaBackoff(void)
 #if OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
     if (mTransmitFrame.mInfo.mTxInfo.mPeriod != 0)
     {
-        uint32_t phaseNow     = (otPlatTimeGet() / kUsPerTenSymbols) % mTransmitFrame.mInfo.mTxInfo.mPeriod;
-        uint32_t phaseDesired = mTransmitFrame.mInfo.mTxInfo.mPhase;
-
         SetState(kStateCslTransmit);
 
-        if (phaseNow < phaseDesired)
+        if (ShouldHandleTransmitTargetTime())
         {
-            mTimer.Start((phaseDesired - phaseNow) * kUsPerTenSymbols);
-        }
-        else if (phaseNow > phaseDesired)
-        {
-            mTimer.Start((phaseDesired + mTransmitFrame.mInfo.mTxInfo.mPeriod - phaseNow) * kUsPerTenSymbols);
+            uint32_t phaseNow =
+                (otPlatRadioGetNow(&GetInstance()) / kUsPerTenSymbols) % mTransmitFrame.mInfo.mTxInfo.mPeriod;
+            uint32_t phaseDesired = mTransmitFrame.mInfo.mTxInfo.mPhase;
+
+            if (phaseNow < phaseDesired)
+            {
+                mTimer.Start((phaseDesired - phaseNow) * kUsPerTenSymbols);
+            }
+            else if (phaseNow > phaseDesired)
+            {
+                mTimer.Start((phaseDesired + mTransmitFrame.mInfo.mTxInfo.mPeriod - phaseNow) * kUsPerTenSymbols);
+            }
+            else
+            {
+                BeginTransmit();
+            }
         }
         else
         {
@@ -759,6 +771,24 @@ exit:
     return swEnergyScan;
 }
 
+bool SubMac::ShouldHandleTransmitTargetTime(void) const
+{
+    bool swTxDelay = true;
+
+    VerifyOrExit(!RadioSupportsTransmitTiming(), swTxDelay = false);
+
+#if OPENTHREAD_CONFIG_LINK_RAW_ENABLE
+    VerifyOrExit(Get<LinkRaw>().IsEnabled(), OT_NOOP);
+#endif
+
+#if OPENTHREAD_CONFIG_LINK_RAW_ENABLE || OPENTHREAD_RADIO
+    swTxDelay = OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE;
+#endif
+
+exit:
+    return swTxDelay;
+}
+
 void SubMac::SetState(State aState)
 {
     if (mState != aState)
diff --git a/src/core/mac/sub_mac.hpp b/src/core/mac/sub_mac.hpp
index b00579a70..3ec42a9dd 100644
--- a/src/core/mac/sub_mac.hpp
+++ b/src/core/mac/sub_mac.hpp
@@ -549,12 +549,14 @@ private:
     bool RadioSupportsRetries(void) const { return ((mRadioCaps & OT_RADIO_CAPS_TRANSMIT_RETRIES) != 0); }
     bool RadioSupportsAckTimeout(void) const { return ((mRadioCaps & OT_RADIO_CAPS_ACK_TIMEOUT) != 0); }
     bool RadioSupportsEnergyScan(void) const { return ((mRadioCaps & OT_RADIO_CAPS_ENERGY_SCAN) != 0); }
+    bool RadioSupportsTransmitTiming(void) const { return ((mRadioCaps & OT_RADIO_CAPS_TRANSMIT_TIMING) != 0); }
 
     bool ShouldHandleTransmitSecurity(void) const;
     bool ShouldHandleCsmaBackOff(void) const;
     bool ShouldHandleAckTimeout(void) const;
     bool ShouldHandleRetries(void) const;
     bool ShouldHandleEnergyScan(void) const;
+    bool ShouldHandleTransmitTargetTime(void) const;
 
     void ProcessTransmitSecurity(void);
     void UpdateFrameCounter(uint32_t aFrameCounter);
diff --git a/src/core/radio/radio_platform.cpp b/src/core/radio/radio_platform.cpp
index 06d8b1b0d..a88b72999 100644
--- a/src/core/radio/radio_platform.cpp
+++ b/src/core/radio/radio_platform.cpp
@@ -158,3 +158,10 @@ OT_TOOL_WEAK uint64_t otPlatRadioGetNow(otInstance *aInstance)
 
     return UINT64_MAX;
 }
+
+OT_TOOL_WEAK uint32_t otPlatRadioGetBusSpeed(otInstance *aInstance)
+{
+    OT_UNUSED_VARIABLE(aInstance);
+
+    return 0;
+}
diff --git a/src/core/thread/csl_tx_scheduler.cpp b/src/core/thread/csl_tx_scheduler.cpp
index cf0d5327d..61cc73f6d 100644
--- a/src/core/thread/csl_tx_scheduler.cpp
+++ b/src/core/thread/csl_tx_scheduler.cpp
@@ -66,6 +66,18 @@ CslTxScheduler::CslTxScheduler(Instance &aInstance)
     , mFrameContext()
     , mCallbacks(aInstance)
 {
+    InitFrameRequestAhead();
+}
+
+void CslTxScheduler::InitFrameRequestAhead(void)
+{
+    uint32_t busSpeedHz = otPlatRadioGetBusSpeed(&GetInstance());
+    // longest frame on bus is 127 bytes with some metadata, use 150 bytes for bus Tx time estimation
+    uint32_t busTxTimeUs = ((busSpeedHz == 0) ? 0 : (150 * 8 * 1000000 + busSpeedHz - 1) / busSpeedHz);
+
+    // Use ceiling to get next closest integer
+    mCslFrameRequestAhead =
+        (OPENTHREAD_CONFIG_MAC_CSL_REQUEST_AHEAD_US + busTxTimeUs + kUsPerTenSymbols - 1) / kUsPerTenSymbols;
 }
 
 void CslTxScheduler::Update(void)
@@ -144,15 +156,14 @@ uint32_t CslTxScheduler::GetNextCslTransmissionDelay(const Child &aChild, uint64
     uint32_t delay;
     uint16_t period_offset = (aRadioNow / kUsPerTenSymbols) % aChild.GetCslPeriod();
 
-    if (aChild.GetCslPhase() > period_offset + kCslFrameRequestAheadThreshold)
+    if (aChild.GetCslPhase() > period_offset + mCslFrameRequestAhead)
     {
-        delay = static_cast<uint16_t>(aChild.GetCslPhase() - period_offset - kCslFrameRequestAheadThreshold) *
-                kUsPerTenSymbols;
+        delay = static_cast<uint16_t>(aChild.GetCslPhase() - period_offset - mCslFrameRequestAhead) * kUsPerTenSymbols;
     }
     else
     {
         delay = static_cast<uint16_t>(aChild.GetCslPeriod() + aChild.GetCslPhase() - period_offset -
-                                      kCslFrameRequestAheadThreshold) *
+                                      mCslFrameRequestAhead) *
                 kUsPerTenSymbols;
     }
 
diff --git a/src/core/thread/csl_tx_scheduler.hpp b/src/core/thread/csl_tx_scheduler.hpp
index d534dcd22..bc16d2979 100644
--- a/src/core/thread/csl_tx_scheduler.hpp
+++ b/src/core/thread/csl_tx_scheduler.hpp
@@ -65,8 +65,7 @@ class CslTxScheduler : public InstanceLocator
 public:
     enum
     {
-        kMaxCslTriggeredTxAttempts     = OPENTHREAD_CONFIG_MAC_MAX_TX_ATTEMPTS_INDIRECT_POLLS,
-        kCslFrameRequestAheadThreshold = 2000 / kUsPerTenSymbols,
+        kMaxCslTriggeredTxAttempts = OPENTHREAD_CONFIG_MAC_MAX_TX_ATTEMPTS_INDIRECT_POLLS,
     };
 
     /**
@@ -187,6 +186,7 @@ public:
     void Clear(void);
 
 private:
+    void InitFrameRequestAhead(void);
     void RescheduleCslTx(void);
 
     uint32_t GetNextCslTransmissionDelay(const Child &aChild, uint64_t aRadioNow);
@@ -197,6 +197,7 @@ private:
 
     void HandleSentFrame(const Mac::TxFrame &aFrame, otError aError, Child &aChild);
 
+    uint32_t                mCslFrameRequestAhead;
     Child *                 mCslTxChild;
     Message *               mCslTxMessage;
     Callbacks::FrameContext mFrameContext;
diff --git a/src/lib/spinel/radio_spinel.hpp b/src/lib/spinel/radio_spinel.hpp
index c228a5a14..8048abf9f 100644
--- a/src/lib/spinel/radio_spinel.hpp
+++ b/src/lib/spinel/radio_spinel.hpp
@@ -669,6 +669,14 @@ public:
      */
     uint64_t GetNow(void);
 
+    /**
+     * This method returns the bus speed between the host and the radio.
+     *
+     * @returns   bus speed in bits/second.
+     *
+     */
+    uint32_t GetBusSpeed(void) const;
+
 private:
     enum
     {
diff --git a/src/lib/spinel/radio_spinel_impl.hpp b/src/lib/spinel/radio_spinel_impl.hpp
index b8f795696..8bd741b6f 100644
--- a/src/lib/spinel/radio_spinel_impl.hpp
+++ b/src/lib/spinel/radio_spinel_impl.hpp
@@ -304,6 +304,9 @@ template <typename InterfaceType, typename ProcessContextType>
 otError RadioSpinel<InterfaceType, ProcessContextType>::CheckRadioCapabilities(void)
 {
     const otRadioCaps kRequiredRadioCaps =
+#if OPENTHREAD_CONFIG_MAC_CSL_TRANSMITTER_ENABLE
+        OT_RADIO_CAPS_TRANSMIT_SEC | OT_RADIO_CAPS_TRANSMIT_TIMING |
+#endif
         OT_RADIO_CAPS_ACK_TIMEOUT | OT_RADIO_CAPS_TRANSMIT_RETRIES | OT_RADIO_CAPS_CSMA_BACKOFF;
 
     otError        error = OT_ERROR_NONE;
@@ -317,10 +320,14 @@ otError RadioSpinel<InterfaceType, ProcessContextType>::CheckRadioCapabilities(v
 
     if ((mRadioCaps & kRequiredRadioCaps) != kRequiredRadioCaps)
     {
-        otLogCritPlat("RCP does not support required capabilities: ack-timeout:%s, tx-retries:%s, CSMA-backoff:%s",
-                      (mRadioCaps & OT_RADIO_CAPS_ACK_TIMEOUT) ? "yes" : "no",
-                      (mRadioCaps & OT_RADIO_CAPS_TRANSMIT_RETRIES) ? "yes" : "no",
-                      (mRadioCaps & OT_RADIO_CAPS_CSMA_BACKOFF) ? "yes" : "no");
+        otRadioCaps missingCaps = (mRadioCaps & kRequiredRadioCaps) ^ kRequiredRadioCaps;
+
+        otLogCritPlat("RCP is missing required capabilities: %s%s%s%s%s",
+                      (missingCaps & OT_RADIO_CAPS_ACK_TIMEOUT) ? "ack-timeout " : "",
+                      (missingCaps & OT_RADIO_CAPS_TRANSMIT_RETRIES) ? "tx-retries " : "",
+                      (missingCaps & OT_RADIO_CAPS_CSMA_BACKOFF) ? "CSMA-backoff " : "",
+                      (missingCaps & OT_RADIO_CAPS_TRANSMIT_SEC) ? "tx-security " : "",
+                      (missingCaps & OT_RADIO_CAPS_TRANSMIT_TIMING) ? "tx-timing " : "");
 
         DieNow(OT_EXIT_RADIO_SPINEL_INCOMPATIBLE);
     }
@@ -1555,17 +1562,20 @@ otError RadioSpinel<InterfaceType, ProcessContextType>::Transmit(otRadioFrame &a
     otPlatRadioTxStarted(mInstance, mTransmitFrame);
 
     error = Request(true, SPINEL_CMD_PROP_VALUE_SET, SPINEL_PROP_STREAM_RAW,
-                    SPINEL_DATATYPE_DATA_WLEN_S                     // Frame data
-                                            SPINEL_DATATYPE_UINT8_S // Channel
-                                            SPINEL_DATATYPE_UINT8_S // MaxCsmaBackoffs
-                                            SPINEL_DATATYPE_UINT8_S // MaxFrameRetries
-                                            SPINEL_DATATYPE_BOOL_S  // CsmaCaEnabled
-                                            SPINEL_DATATYPE_BOOL_S  // IsARetx
-                                            SPINEL_DATATYPE_BOOL_S, // SkipAes
+                    SPINEL_DATATYPE_DATA_WLEN_S                               // Frame data
+                                                    SPINEL_DATATYPE_UINT8_S   // Channel
+                                                    SPINEL_DATATYPE_UINT8_S   // MaxCsmaBackoffs
+                                                    SPINEL_DATATYPE_UINT8_S   // MaxFrameRetries
+                                                    SPINEL_DATATYPE_BOOL_S    // CsmaCaEnabled
+                                                    SPINEL_DATATYPE_BOOL_S    // IsARetx
+                                                    SPINEL_DATATYPE_BOOL_S    // SkipAes
+                                                    SPINEL_DATATYPE_UINT16_S  // Period
+                                                    SPINEL_DATATYPE_UINT16_S, // Phase
                     mTransmitFrame->mPsdu, mTransmitFrame->mLength, mTransmitFrame->mChannel,
                     mTransmitFrame->mInfo.mTxInfo.mMaxCsmaBackoffs, mTransmitFrame->mInfo.mTxInfo.mMaxFrameRetries,
                     mTransmitFrame->mInfo.mTxInfo.mCsmaCaEnabled, mTransmitFrame->mInfo.mTxInfo.mIsARetx,
-                    mTransmitFrame->mInfo.mTxInfo.mIsSecurityProcessed);
+                    mTransmitFrame->mInfo.mTxInfo.mIsSecurityProcessed, mTransmitFrame->mInfo.mTxInfo.mPeriod,
+                    mTransmitFrame->mInfo.mTxInfo.mPhase);
 
     if (error == OT_ERROR_NONE)
     {
@@ -1806,5 +1816,11 @@ uint64_t RadioSpinel<InterfaceType, ProcessContextType>::GetNow(void)
     return mIsTimeSynced ? (otPlatTimeGet() + static_cast<uint64_t>(mRadioTimeOffset)) : UINT64_MAX;
 }
 
+template <typename InterfaceType, typename ProcessContextType>
+uint32_t RadioSpinel<InterfaceType, ProcessContextType>::GetBusSpeed(void) const
+{
+    return mSpinelInterface.GetBusSpeed();
+}
+
 } // namespace Spinel
 } // namespace ot
diff --git a/src/ncp/ncp_base_radio.cpp b/src/ncp/ncp_base_radio.cpp
index 8d3d4499d..25a349ec8 100644
--- a/src/ncp/ncp_base_radio.cpp
+++ b/src/ncp/ncp_base_radio.cpp
@@ -398,6 +398,8 @@ otError NcpBase::DecodeStreamRawTxRequest(otRadioFrame &aFrame)
     aFrame.mInfo.mTxInfo.mCsmaCaEnabled       = true;
     aFrame.mInfo.mTxInfo.mIsARetx             = false;
     aFrame.mInfo.mTxInfo.mIsSecurityProcessed = false;
+    aFrame.mInfo.mTxInfo.mPeriod              = 0;
+    aFrame.mInfo.mTxInfo.mPhase               = 0;
 
     // All the next parameters are optional. Note that even if the
     // decoder fails to parse any of optional parameters we still want to
@@ -409,6 +411,8 @@ otError NcpBase::DecodeStreamRawTxRequest(otRadioFrame &aFrame)
     SuccessOrExit(mDecoder.ReadBool(csmaEnable));
     SuccessOrExit(mDecoder.ReadBool(isARetx));
     SuccessOrExit(mDecoder.ReadBool(isSecurityProcessed));
+    SuccessOrExit(mDecoder.ReadUint16(aFrame.mInfo.mTxInfo.mPeriod));
+    SuccessOrExit(mDecoder.ReadUint16(aFrame.mInfo.mTxInfo.mPhase));
     aFrame.mInfo.mTxInfo.mCsmaCaEnabled       = csmaEnable;
     aFrame.mInfo.mTxInfo.mIsARetx             = isARetx;
     aFrame.mInfo.mTxInfo.mIsSecurityProcessed = isSecurityProcessed;
diff --git a/src/posix/platform/hdlc_interface.cpp b/src/posix/platform/hdlc_interface.cpp
index 9ae3573b4..586678af7 100644
--- a/src/posix/platform/hdlc_interface.cpp
+++ b/src/posix/platform/hdlc_interface.cpp
@@ -134,6 +134,7 @@ HdlcInterface::HdlcInterface(SpinelInterface::ReceiveFrameCallback aCallback,
     , mReceiveFrameContext(aCallbackContext)
     , mReceiveFrameBuffer(aFrameBuffer)
     , mSockFd(-1)
+    , mBaudRate(0)
     , mHdlcDecoder(aFrameBuffer, HandleHdlcFrame, this)
 {
 }
@@ -563,6 +564,8 @@ int HdlcInterface::OpenFile(const RadioUrl &aRadioUrl)
             break;
         }
 
+        mBaudRate = baudrate;
+
         if (aRadioUrl.GetValue("uart-flow-control") != nullptr)
         {
             tios.c_cflag |= CRTSCTS;
diff --git a/src/posix/platform/hdlc_interface.hpp b/src/posix/platform/hdlc_interface.hpp
index 2db2400e2..ef93a669c 100644
--- a/src/posix/platform/hdlc_interface.hpp
+++ b/src/posix/platform/hdlc_interface.hpp
@@ -148,6 +148,14 @@ public:
     void Process(const VirtualTimeEvent &aEvent) { Decode(aEvent.mData, aEvent.mDataLength); }
 #endif
 
+    /**
+     * This method returns the bus speed between the host and the radio.
+     *
+     * @returns   Bus speed in bits/second.
+     *
+     */
+    uint32_t GetBusSpeed(void) const { return mBaudRate; }
+
 private:
     /**
      * This method instructs `HdlcInterface` to read and decode data from radio over the socket.
@@ -198,7 +206,7 @@ private:
     static void HandleHdlcFrame(void *aContext, otError aError);
     void        HandleHdlcFrame(otError aError);
 
-    static int OpenFile(const RadioUrl &aRadioUrl);
+    int OpenFile(const RadioUrl &aRadioUrl);
 #if OPENTHREAD_POSIX_CONFIG_RCP_PTY_ENABLE
     static int ForkPty(const char *aCommand, const char *aRadioUrl);
 #endif
@@ -214,6 +222,7 @@ private:
     Spinel::SpinelInterface::RxFrameBuffer &      mReceiveFrameBuffer;
 
     int           mSockFd;
+    uint32_t      mBaudRate;
     Hdlc::Decoder mHdlcDecoder;
 
     // Non-copyable, intentionally not implemented.
diff --git a/src/posix/platform/radio.cpp b/src/posix/platform/radio.cpp
index 721f71100..d2a1bfb24 100644
--- a/src/posix/platform/radio.cpp
+++ b/src/posix/platform/radio.cpp
@@ -508,3 +508,9 @@ uint64_t otPlatRadioGetNow(otInstance *aInstance)
     OT_UNUSED_VARIABLE(aInstance);
     return sRadioSpinel.GetNow();
 }
+
+uint32_t otPlatRadioGetBusSpeed(otInstance *aInstance)
+{
+    OT_UNUSED_VARIABLE(aInstance);
+    return sRadioSpinel.GetBusSpeed();
+}
diff --git a/src/posix/platform/spi_interface.hpp b/src/posix/platform/spi_interface.hpp
index de3414530..06cdca7b4 100644
--- a/src/posix/platform/spi_interface.hpp
+++ b/src/posix/platform/spi_interface.hpp
@@ -138,6 +138,14 @@ public:
      */
     void Process(const RadioProcessContext &aContext);
 
+    /**
+     * This method returns the bus speed between the host and the radio.
+     *
+     * @returns   Bus speed in bits/second.
+     *
+     */
+    uint32_t GetBusSpeed(void) const { return ((mSpiDevFd >= 0) ? mSpiSpeedHz : 0); }
+
 private:
     int     SetupGpioHandle(int aFd, uint8_t aLine, uint32_t aHandleFlags, const char *aLabel);
     int     SetupGpioEvent(int aFd, uint8_t aLine, uint32_t aHandleFlags, uint32_t aEventFlags, const char *aLabel);
diff --git a/tests/scripts/expect/v1_2-rcp.exp b/tests/scripts/expect/v1_2-rcp.exp
new file mode 100755
index 000000000..9edac4937
--- /dev/null
+++ b/tests/scripts/expect/v1_2-rcp.exp
@@ -0,0 +1,73 @@
+#!/usr/bin/expect -f
+#
+#  Copyright (c) 2020, The OpenThread Authors.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#  1. Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#  3. Neither the name of the copyright holder nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+
+source "tests/scripts/expect/_common.exp"
+
+set node_1 [spawn_node 1]
+set spawn_id $node_1
+
+send "panid 0xface\n"
+expect "Done"
+send "ifconfig up\n"
+expect "Done"
+send "thread start\n"
+expect "Done"
+wait_for "state" "leader"
+expect "Done"
+
+send "ipaddr\n"
+expect -re {(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4})}
+set addr $expect_out(1,string)
+expect "Done"
+
+spawn $env(MTD_COMMAND) "2"
+set node_2 $spawn_id
+expect_after {
+    timeout { exit 1 }
+}
+
+send "panid 0xface\n"
+expect "Done"
+send "mode s\n"
+expect "Done"
+send "csl period 5000\n"
+expect "Done"
+send "ifconfig up\n"
+expect "Done"
+send "thread start\n"
+expect "Done"
+wait_for "state" "child"
+expect "Done"
+send "ping $addr\n"
+expect "16 bytes from $addr: icmp_seq=1"
+
+dispose
+
+set spawn_id $node_1
+dispose
diff --git a/tests/toranj/openthread-core-toranj-config.h b/tests/toranj/openthread-core-toranj-config.h
index 15c6ff36f..989033c75 100644
--- a/tests/toranj/openthread-core-toranj-config.h
+++ b/tests/toranj/openthread-core-toranj-config.h
@@ -462,4 +462,12 @@
  *
  */
 #define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_SECURITY_ENABLE 1
+
+/**
+ * @def OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE
+ *
+ * Define to 1 to enable software transmission target time logic.
+ *
+ */
+#define OPENTHREAD_CONFIG_MAC_SOFTWARE_TX_TIMING_ENABLE 1
 #endif // OPENTHREAD_RADIO